Boiler pressure low

Boiler pressure dropping! What are the causes of losing boiler pressure ?

Boiler pressure low

Boiler pressure safety switch Vaillant Eco-tec.

A guide to why your system pressure  is dropping? Do not ignore this!

Boiler pressure dropping is something we encounter very frequently, especially during the heating season.

Central heating system which incorporate a pressure gauge and a filling loop are called sealed systems and should not lose pressure consistently.

Sealed system means exactly that!

Once all the air is bleed out of the heating system the pressure in the system should stay stable because the water has no where to go.

The central heating water circulates around the radiators and boiler every time you turn it on and unless you bleed a radiator or you have a leak the water has no way of escaping.

Boiler pressure dropping, what are the causes of system pressure lose?

The following steps will guide you through some basic steps to understand what is causing this drop.

If you cannot resolve this yourself using our guide below we are on hand to step in should you require some professional intervention.

1-You have a leak on your heating system!

You have a leak somewhere on the central heating circuit! This includes radiators, radiators valves and all connecting pipework.

Unfortunately this does sometimes mean pipework which is not visible, either underneath timber floors or screed.

Customer action! -Check all visible joints including radiator valves and connections for obvious signs of leaks. If you feel confident in doing so turn off the isolation valves for the heating circuit underneath the boiler as shown below. This will temporarily leave you without heating however this will prove whether your leak is on the heating circuit or boiler. If the pressure stays stable after shutting off the valves and you cannot find any obvious leaks then your leak is in the floor somewhere and you may require our assistance.


2-You have a faulty pressure relief valve!

You have a faulty pressure relief valve either inside the boiler or on an external pressure relief valve. Pressure relief valves are designed to let out excess pressure in the event of over pressure usually when the boiler exceeds 3 bar. When they fail they will leak water from the central heating system at a much lower pressure to a copper pipe terminated outside of the property.

Customer action!- Look externally for a small copper pipe exiting your property usually close to the boiler or cylinder location. This is the pressure relief pipe exiting to atmosphere.

You are looking to see if this is dripping while you have pressure in the system. If it is call us, this is not a DIY job.

3-You have a faulty expansion vessel

You have a faulty expansion vessel- This means your boiler pressure will exceed 3 bar during the heating up process.

This is because the expansion of water in the system has nowhere to go due to the expansion vessel failure. Pressure  increases exponentially with temperature so once  the pressure reaches 3 bar the pressure relief valve will expel the excess pressure from the system until it reaches a safe point. When the system cools down you will find the water lost will now show on the pressure gauge as a significant drop. Very similar to the above scenarios, as if the system has a leak and will also cause the boiler to lock out and break down once cooled.

Customer action!-Run the central heating system up to full temperature and check to see if the pressure gauge rises. If it does shut the boiler off immediately and contact us. Replacing an expansion vessel is not a DIY job either. It is also good practice to replace the pressure relief valve at the same time.

This is due to the wear and tear caused from the valve opening and shutting and may not reset once its been activated too many times.

4-The leak is inside the boiler!

The leak is inside the boiler! Weak points on boilers are as follows: Automatic air vents,  O rings joints, washers, divertor valves and heat exchnagers.

In most cases the boiler leak will eventually drip out of the bottom and be quite obvious but in not in all cases. Small Internal leaks do not always leak

out of the boiler because the drip may be dripping onto another surface which is catching the leak.

The leak can also be disguised by running down a pipe which may not be obvious or the leak can  evaporate while the boiler is hot.

Customer action!- If you see a leak coming from the bottom of the boiler turn the electrical supply off to the boiler immediately as the leak can very easy leak into the electrical control box of the boiler and inflict expensive damage. If you have followed all the other steps and by a process of elimination come to the conclusion that the leak is inside the boiler, call us.  We will service the boiler and provide a quote to repair the leak.

Do not take the case off of the boiler yourself in any circumstances as this may contravene Gas safety regulations.

5-You have bled the air out of your radiators!

You have bled your radiator system to remove air from the the top of a radiator. In turn this drops the system pressure and must be replaced by introducing fresh water into the system via the filling loop.

Customer Action!- If you have never done this before there are many You tube video tutorials.

Here is one for an Vaillant Eco-tec plus boiler which has an internal filling loop.

There are many to choose from including the tutorials from on our own You Tube channel.  Remember when re-pressurising a system after bleeding radiators, take care to not over presssurise the system.  To be on the safe side, stick to 1 bar of pressure and then monitor for two weeks to ensure you do not have any leaks on the system which may have lead to the air to build up in the tops of the radiators in the first place.

I hope this guide has been helpful.

If you do have further questions or would like a site visit please contact us. We are more than happy to provide advice over the phone which costs nothing.

Written by Dean Dawe MD

Combi Boilers

Combi Boilers – What are the pros and cons?

Combi Boilers, the pros and cons… this is a question I get asked a lot when helping customers choose the right boiler for their property.
Hopefully this article will help to make the facts a bit clearer so you can understand the pros and cons of a combi boiler installation before making a decision.
Many people I go and see will say to me right from the off ‘I would like a combi boiler please’ without really understanding the negative aspects of a combi verses other choices that may be available.

Combi Boilers

Combi Boilers – The Pros ✔

☻      A Combi boiler in most cases removes the requirement for a cold water storage tank in the loft. This is because the previously stored cold water services from the tank are converted onto the mains supply dramatically increasing the pressure to taps and showers in the house.

☻      Removing the water tank also frees up space in the loft for storage or a conversion leaving you with whats called a dry loft. No water services in the loft reduces the risk of water tanks or pipework leaking through the ceiling in future so provides peace of mind!

☻  As part of a combi boiler conversion the hot water cylinder is also usually removed, freeing up a handy storage space.

☻ A combi boiler provides hot water on demand, in other words when the hot tap is turned on the boiler will fire and send hot water to the tap. In theory you should only be paying for the hot water you use and need. With a traditional hot water system the boiler heats the cylinder and the stored water sits there until it is drawn off, so there is always the risk of water being heated unnecessarily, if not exhausted before it cools down.

☻ A combi boiler also increases the hot water pressure to all taps and showers, which once combined with the increased cold water pressure is a big perk of removing your tank fed system. Showers will automatically become power showers, compared to a standard non pumped traditional system and taps miraculously come to life!

☻ Due to the cold water main now being the primary source to all taps, you can now drink it! Very handy in the night should you wish to grab a drink of water and your bathroom is closer to your bedroom than the kitchen.


Combi Boilers – The Cons ✘

☹   Combi Boilers can only provide a limited volume of hot water to taps and showers, therefore unsuitable for properties with more than two bathrooms. If a combi boiler for instance, can deliver 18 litres per minute, which is about the maximum performance achievable right now, the 18 litres per minute has to be shared between what ever is being drawn off it. For example, with this boiler you could run two showers, each one achieving 9 litres per minute flow rate. If you were for instance running a bath, all of the performance (18 litres per minute) would be required to run that bath in a sensible amount of time. 

☹ Combi boilers and mains water systems in general are totally reliant on the pressure and flow rate to the house. It needs to be adequate enough to cope with all the cold water and hot water running from the same supply. The classic mistake we see, many plumbers do not check this first and install combination boilers in houses which should never have had the cold water storage tank removed in the first place due to low mains water flow rate. So, if you have 12 litres per minute coming into your property and your combi boiler is sized to heat 12 litres per minute, as soon as someone else turns on another tap in the house or a washing machine, it will starve the combi boiler of water. If this happens and you are in the shower, it will just trickle out for a while or stop completely until full pressure is restored to the shower. 

Here is the simple test we do on a site survey to check you have adequate flow rate to your house. 

☹ Combi boilers do not have a back up, so in the event that the boiler breaks, in most cases you will lose both heating and hot water until the boiler is repaired.

Bringing your hot water and heating into one nice neat box does have its downsides. Some clients negate this by also Installing an electric shower which does not need the boiler to provide hot water and will work independently. 

☹ Hot water will take a long time to reach taps or showers when hot water draw offs are a considerable distance away from the combi boiler.

This can be  frustrating and wastes water on a grand scale! TIP-Look at the proposed location for the combi boiler and then the furthest tap away from the boiler location. If for example you are thinking of Installing combi boiler on on the ground floor of a town house and there is  a bathroom on the 2nd floor you will experience this problem and worth avoiding . This is the reason why hot water cylinders are usually sited in the central of  property to distribute hot water quickly to the taps.

☹ Combi boilers are much more prone to scaling up as the plate heat exchanger fitted to this type of boiler have very narrow water ways. This can be addressed by fitting  water softeners and magnetic system filters on the heating side. A clean combi boiler is a happy boiler!

☹ Modern combi boilers do not have as long a life span as a traditional system and they can become inefficient to repair near the end of their life. The best advice is to get the longest manufacturers warranty you can at the outset and keep the boiler regularly maintained with an annual boiler service. A good quality combination boiler depending on the amount of use should last 10 to 12 years.

I hope this article has been informative and although this post was not meant as an advert we would of course welcome anybody who is thinking of upgrading their boiler to contact us via the contact page or give us a call on 0800 2851920.

The purpose of this article is to educate and provide honest advice based on the facts and 25 years in the business. If you feel it has done that please LIKE AND SHARE the article from our Facebook page.

Thank you, Dean 



Worcester Bosch 0% Interest Combi Boiler Deal

Sometimes boilers reach the end of their useful life or are uneconomical to repair

The law of sod dictates that your boiler goes down at just the wrong time! Possibly when finances are stretched to the max with the day to day expense of family life.

We understand this, and working with Worcester Bosch, have come up with our cheapest combi boiler swap with examples below of how you could split the payments over 10 months inter-steels free.

You can put down any deposit and the rest of the payments are equally divided into ten.

The example below is our current special offer to show a real life example, but the same process can be implemented on any value of money as long as we are fitting a Worcester boiler.

This means you could use the finance for a complete heating system or a complete overhaul of boiler and controls!

Worcester Bosch 25i Combination Boiler ERP for £2325 inc VAT


This offer includes:

  • Boiler
  • Standard Flue Kit
  • System Filter 22mm
  • Boiler Plus Compliant Honeywell Wireless Programmable Digital Room Thermostat 
  • Pipework And Fittings
  • Inhibitor
  • Building Regulations Compliance Certificate
  • 10 Year Warranty

Representative example:

Total Cash Price of Goods and Services  £ 2,325.00

Advance Payment (Deposit)                      £ 0

Loan Advance                                              £ 2,325.00

Duration of Loan                                        10 Months

Monthly Repayment                                   £ 232.50

Total Charge for Credit                               £ 0

Total Amount Payable                                £ 2,325.00

APR                                                                0%

The check your eligibility for the finance please click here

…or to take advantage of this latest offer please get in touch now! 


Commercial Boiler Installation Greenhithe

We were approached at the end of last year by Belmont Healthcare who own and manage residential care homes throughout the south of England.

They are very good at looking after patients suffering from dementia or other brain related illnesses and specialize in turning around failing care homes.

Our first project with them was to design and install a new boiler system to replace the aging Keston boilers which had past their sell by date on Greenhithe site.

They also had many other issues related to radiators not heating fully and not having proper control of the heating zones.

We removed this mess and replaced with two Vaillant ecoTEC boilers mated to Vaillant’s plate heat exchanger. This provides separation from the aging heating system and avoids any debris in the radiators entering the boilers and causing reliability issues.

We then used Vaillant VRC 700 along side VR70 and VR71 control modules which wire into all the existing heating and hot water zones to provide total control and automation of all zones.

The weather compensation cleverly detects when the outside temperature is warmer and the controller reduces the flow temperature of the boilers according, saving hundreds of pounds every year on gas!

This is a very basic Vaillant boiler commercial setup, however it was just what the client was looking for in this instance as cost of installation was also a big factor in us winning the job.

We are now surveying two other care homes on the south coast for Belmont Healthcare and looking for smart ways we can save the client big money on fuel bills on those sites as well!



This is what we do in a nut shell, look for cunning ways to save energy and in turn save you money!

If you have any sort of installation where you feel you are paying over the top on your fuel bills I’m sure there is a way we can assist, please give us a call today.


Alpha Combination Boiler Deal !!

Alpha Evoke Deal !!

For a limited time only we are offering an amazing special offer.
The new Alpha Evoke 28kW combination boiler, supplied and fitted in your home for £1200 +VAT

Please read terms and conditions to ensure your current installation is eligible for the offer.

This offer includes:

  • Boiler
  • Standard Flue Kit
  • Boiler Plus Compliant 7 Day Thermostat
  • Materials
  • Inhibitor
  • Building Regulations Compliance Certificate
  • 6 Year Warranty

The Alpha Evoke key features!

Stainless steel heat exchanger

High efficiency Grundfos pump and hydroblock assembly

Single electrode

Easy-access dry-change NTCs

Combined condensate and pressure relief valve connection

Zinc plated expansion vessel to prevent corrosion

For more info click here

This offer is subject to the following conditions:

The boiler must replace an existing combination boiler in the same position.

The existing gas pipe  must be of adequate size to supply the new boiler.

The flue must already be a standard type on an outside wall, and not require any further accessories to meet regulations.

The central system heating system we are connecting to must be clean enough to not require a power flush.

If any further works or accessories are required, we can still give you the special offer price and add the extra items on the total price.

If interested use our contact form or call us on 0800 2851920

Combination Boiler

Combination Boiler With 13 Year Warranty!

For the first time ever a boiler manufacturer is offering an incredible 13 year warranty

Alpha boilers have very generously increased the warranty on the E-Tec range from 10 to 13 years.

What’s the catch?

There isn’t one really.

The only stipulations are that:

  • The boiler is fitted with Alpha’s premier filter kit. (which protects the boiler from debris ingress)
  • The boiler is serviced every year. (by a qualified gas safe operative who is trained to work on Alpha boilers)

If you are replacing your aging combination boiler like for like you should budget between £2000 and £2500 for a direct upgrade.

This would include flue, upgraded controller and flushing the radiators.

Register your interest through our contact form or call us on 0800 2851920

Nest Cam IQ Outdoor

Is The Nest IQ Camera For Me?

The answer really depends on possible siting opportunities.

The Nest IQ camera works best if it’s mounted facing people walking towards your property. 

The facial recognition function learns quicker if the camera can zoom onto faces front on.

Once it has recognized certain family members you can turn off the notifications and only have unfamiliar faces sending you alerts.









The key thing about the installation?

Having the power supply in close proximity to where the camera is ideally positioned.

When pricing to install Nest IQ cameras I do often find a socket close by.

However, getting the cable neat without the use of something to disguise it is more challenging.

We are Nest Pro installers at Cloverleaf.

If you are in any doubt about whether any of the Nest products are for you please don’t hesitate to call us!

All our advice is free and impartial!

If we do not feel you’ll receive value for money and get the full benefit of the Nest product you are thinking about we will be honest and tell you.

We pride ourselves on giving the right advice.

Use our contact form here for help.


Commercial Boiler Servicing Orpington

We have recently been charged with the responsibility of looking after the commercial boilers at Kevington Hall in Orpington.

This year we have carried out the appropriate servicing to nurse them through the winter months as the cold weather is nearly upon us.

We do not want to disrupt the occupants as the cold weather arrives so holding back on overhauling the plant room and boilers until Spring 2019.

We are working with the client to give Kevington Hall the most efficient system boiler system and controls out there.

The plant room will look very different once we have done our refurbishment work. Watch this space.


For all commercial boilers, upgrades or servicing inquiries, please call us now or send us through a call back request via the contact page.

We have successfully designed and installed commercial boilers in schools, churches and business premises around Orpington and other places in the London and Kent area.


Boiler Plus Legislation

Boiler Plus Legislation: New standards for domestic boiler installations

From 6th April 2018 the legislation around heating manufacture and installation in the UK is changing, and there are some big changes.

These changes have been named Boiler Plus and are being introduced by the Department for Business, Energy and Industrial Strategy (BEIS). They address the energy efficiency of heating systems and have raised the bar for both manufacturers and installers.

  • Gas boiler performance: space heating efficiency of the new boiler no less than ErP 92%
  • Time and temperature control required for all gas and oil boiler installations
  • Combi boiler installations must also include one of the following: Weather compensation, Load compensation, Flue Gas Heat Recovery, Smart controls.


The most notable change applies to the minimum performance standard for domestic gas boilers in England. The minimum efficiency level of all boilers manufactured and installed will be set ar 92% ErP. The main motivation behind the change is to phase out inefficient boilers and reduce carbon emissions in line with targets set by the EU. It forms just part of a wider plan known as the Government’s Clean Growth Strategy which aims to combat climate change and provide UK homes with greater comfort and lower energy bills.

What will happen to homeowners and installers who do not comply?

Installers who fail to install boilers in line with these new Building Regulations will be breaking the law and could be prosecuted by Building Control. The Gas Safe Register can also refer safety concerns to the HSE (Health and Safety Executive). Invoicing a customer for work which they claim to be legal but is not is also to be considered fraudulent under Trading Standards.

Homeowners who knowingly allow non-compliant work to be carried out could also face prosecution and fines of up to £5,000.

What is FGHR? A Flue Gas Heat Recovery (FGHR) is a device designed to improve energy efficiency of the boiler by recycling the heat from the flue gases which would usually be lost into the atmosphere. Instead this heat is used it to preheat domestic hot water.

What is weather compensation? Weather compensation devices enable the boiler to read the outside temperature via a sensor so that the boiler can adjust the temperature of your heating accordingly.

What is load compensation? Load compensation measures the response of the heating system and adjusts the flow temperature based on what is needed to reduce fuel consumption.

Why are these changes being introduced?

This legislation is designed to help the UK meet the targets by 2020. More than £2.5 billion of Government funding was designated towards lowering carbon emissions for the period 2015 – 2021.

Greg Clark, Business and Energy Secretary, said:

“This Government has put clean growth at the heart of its Industrial Strategy to increase productivity, boost people’s earning power and ensure Britain continues to lead the world in efforts to tackle climate change.

“For the first time in a generation, the British government is leading the way on taking decisions on new nuclear, rolling out smart meters and investing in low carbon innovation. The world is moving from being powered by polluting fossil fuels to clean energy. It’s as big a change as the move from the age of steam to the age of oil and Britain is showing the way.”

Some of the measures taken include:

  • Investment of around £3.6 billion to upgrade around a million homes through the Energy Company Obligation (ECO) including extended support for home energy efficiency improvements from 2022 to 2028
  • Upgrading all fuel poor homes to Energy Performance Certificate Band C by 2030 with as many homes as possible to be Energy Performance Certificate Band C by 2035
  • Improve the energy performance standards of privately rented homes to Energy Performance Band C by 2030.


Mega Flow Installation Grove Park

Mega Flow Installation Grove Park

We thought we would share this new Mega flow Installation with you in Grove Park.

One of the builders we work for, namely Rixon & Rixon, converted a three bedroom house into a 6 bedroom property along Grove Park Road.

With the amount of bathrooms Installed it required a hot water solution to cope with high hot water demand and decent flow rate to all taps.

When high flow rate is a priority we will always recommend Heat Rae Sadia Mega flow.

In eyes our this is the industry leader in terms of performance and quality.










If you are struggling for hot water pressure in your property please call us and we’ll be happy to offer free advice and planning to suit your family’s requirements.