Vaillant British Gas boiler under warranty

[Deleted User]

LondonS30 said:

Olly_J said:

LondonS30 said:

The filling loop is definitely closed. We checked this first and he has since checked it as well. 

Where else can water enter the system from?

The filling loop is the only point of entry, but it is possible they can become faulty and not close off the supply, even when they appear closed, dirt or debris preventing a tight seal etc so water still seeps in, as its under 2 bar of pressure or so. If you were to turn off the stop outside, run a tap for a bit to release pipe pressure then re-check your boiler that should tell you if its the issue or not

Do you have a pressure gauge on the boiler side pipe work or are you relying on the boiler display itself?

Thanks. I only have the boiler display but the engineer has been checking the pressure directly from the boiler itself (not relying on the display) and that is reading high. Even without turning on heating or taps - the pressure rises up and goes up to above 3 and up to 4.5!

He keeps saying how dirty the system is and keeps talking about a Powerflush (which i already paid for when boiler was installed 3 years ago). Whilst i accept a dirty system can cause issues and cause parts to fail - I don’t think it’s the sole problem!!

I will double check but I think he would have replaced the filling loop before all the other components (hopefully). If it was an issue with debris in the filling loop (even if closed) and you replaced it, would that fix the issue/ normalise the pressure? Thanks 

There is a simple way to check if ‘top up’ water is entering the system via the filling loop. Bleed a radiator until the pressure gauge in the boiler falls to, say, 1 Bar. Then sit back and see if it rises. Ideally, do this when the boiler is off and the radiators are cold.

I struggle to see why the engineer thinks that it might be the heat exchanger but I am not a heating engineer.

Olly_J

A boiler can't really create much of its own pressure, aside from the slight increase you'll see with the thermal expansion of water as it heats up and the pump running, so if the pressure is climbing on a meter independent of the boiler itself, then in my mind you have to be seeing an influx of water main pressure into the boiler system.

I think the upper max for Valiant boilers is around 2.8bar which is considered toward danger level, so I would not be surprised if that has damaged the seals causing your leaks, given you are seeing values of up to 4.5. With regards to the dirt you might want to check they have installed a magnetic filter in the system, as that should catch a lot of the usual metallic debris, and have enough inhibitor added to help stop it being generated in the first place

[Deleted User]

Olly_J said:

A boiler can't really create much of its own pressure, aside from the slight increase you'll see with the thermal expansion of water as it heats up and the pump running, so if the pressure is climbing on a meter independent of the boiler itself, then in my mind you have to be seeing an influx of water main pressure into the boiler system.

I think the upper max for Valiant boilers is around 2.8bar which is considered toward danger level, so I would not be surprised if that has damaged the seals causing your leaks, given you are seeing values of up to 4.5. With regards to the dirt you might want to check they have installed a magnetic filter in the system, as that should catch a lot of the usual metallic debris, and have enough inhibitor added to help stop it being generated in the first place

I was hoping that no one would bring that up as boiler warranties do not cover faults arising from debris from the heating system. 

From the Valliant Warranty Document:

15. If any failure is caused by contaminated water in the boiler (e.g. blockages, or influences of flux residues, iron oxides, limescale, sludge etc.) the engineer’s visit becomes chargeable at the prevailing rates.

The website also states:

Your Vaillant guarantee covers you for the repair of any defects related to the manufacture of your Vaillant appliance. The repair has to be completed by one of our Vaillant Service Engineers and will cover both parts and labour.

LondonS30

[Deleted User] said:

LondonS30 said:

Olly_J said:

LondonS30 said:

The filling loop is definitely closed. We checked this first and he has since checked it as well. 

Where else can water enter the system from?

The filling loop is the only point of entry, but it is possible they can become faulty and not close off the supply, even when they appear closed, dirt or debris preventing a tight seal etc so water still seeps in, as its under 2 bar of pressure or so. If you were to turn off the stop outside, run a tap for a bit to release pipe pressure then re-check your boiler that should tell you if its the issue or not

Do you have a pressure gauge on the boiler side pipe work or are you relying on the boiler display itself?

Thanks. I only have the boiler display but the engineer has been checking the pressure directly from the boiler itself (not relying on the display) and that is reading high. Even without turning on heating or taps - the pressure rises up and goes up to above 3 and up to 4.5!

He keeps saying how dirty the system is and keeps talking about a Powerflush (which i already paid for when boiler was installed 3 years ago). Whilst i accept a dirty system can cause issues and cause parts to fail - I don’t think it’s the sole problem!!

I will double check but I think he would have replaced the filling loop before all the other components (hopefully). If it was an issue with debris in the filling loop (even if closed) and you replaced it, would that fix the issue/ normalise the pressure? Thanks 

There is a simple way to check if ‘top up’ water is entering the system via the filling loop. Bleed a radiator until the pressure gauge in the boiler falls to, say, 1 Bar. Then sit back and see if it rises. Ideally, do this when the boiler is off and the radiators are cold.

I struggle to see why the engineer thinks that it might be the heat exchanger but I am not a heating engineer.

Thanks. We did do quite a lot of radiator bleeding before calling BG. We took pressure down to about 1.2. Had to turn boiler off and then on in order for us to read the pressure. Despite bleeding litres from the radiator, when turned back on (without heating or water on), the pressure continued to climb...

I did explain all of this to the engineer as soon as he arrived and reminded him

I just feel he is just replacing XYZ without really thinking through the issue. And none of what he has replaced so far has normalised the pressure..

LondonS30

[Deleted User] said:

Olly_J said:

A boiler can't really create much of its own pressure, aside from the slight increase you'll see with the thermal expansion of water as it heats up and the pump running, so if the pressure is climbing on a meter independent of the boiler itself, then in my mind you have to be seeing an influx of water main pressure into the boiler system.

I think the upper max for Valiant boilers is around 2.8bar which is considered toward danger level, so I would not be surprised if that has damaged the seals causing your leaks, given you are seeing values of up to 4.5. With regards to the dirt you might want to check they have installed a magnetic filter in the system, as that should catch a lot of the usual metallic debris, and have enough inhibitor added to help stop it being generated in the first place

I was hoping that no one would bring that up as boiler warranties do not cover faults arising from debris from the heating system. 

From the Valliant Warranty Document:

15. If any failure is caused by contaminated water in the boiler (e.g. blockages, or influences of flux residues, iron oxides, limescale, sludge etc.) the engineer’s visit becomes chargeable at the prevailing rates.

The website also states:

Your Vaillant guarantee covers you for the repair of any defects related to the manufacture of your Vaillant appliance. The repair has to be completed by one of our Vaillant Service Engineers and will cover both parts and labour.

Oh dear! I really don’t understand - sorry if I’m missing something but my warranty is with British Gas technically. They have not charged me for any of the parts or Labour even though engineer has said the system is “dirty.” How is anyone meant to know how “dirty” the system is beforehand?! I live in London so probably lots of debris and limescale as well. 

So if someone gets a Vaillant boiler through BG - and a BG engineer does the work does that invalidate the warranty? Does not make any sense 

nadsat

As said the simple thing could be the filling loop tap. Ours seemed closed but it was letting water in. It\s a rather flimsy small plastic handle on the pipe.  

nadsat

LondonS30 said:

Oh dear! I really don’t understand - sorry if I’m missing something but my warranty is with British Gas technically. They have not charged me for any of the parts or Labour even though engineer has said the system is “dirty.” How is anyone meant to know how “dirty” the system is beforehand?! I live in London so probably lots of debris and limescale as well. 

So if someone gets a Vaillant boiler through BG - and a BG engineer does the work does that invalidate the warranty? Does not make any sense 

When BG installed the boiler it should have given you a Vaillant guarantee certificate or document. That's what we have. BG may well have an arrangement with Vaillant on repairs under guarantee but our (Vaillant authorised) installer won't touch anything that is a component failure unrelated to the rest of the system as that is what the guarantee is for. Ours is for 10 years I think. 

daveyjp

Problems early on can often be down to a faulty component or the boiler not being fitted correctly in the first place.

I would personally be on to Vaillant as warranty provider and ask for one of their engineers to visit.  Simply swapping out parts is a game of pot luck.

There is an analogue pressure gauge on these boilers, which is the only one you can trust as the display one relies on a sensor which can fail and give a false reading, but the analogue gauge is under the cover - a stupid design.

[Deleted User]

LondonS30 said:

[Deleted User] said:

Olly_J said:

A boiler can't really create much of its own pressure, aside from the slight increase you'll see with the thermal expansion of water as it heats up and the pump running, so if the pressure is climbing on a meter independent of the boiler itself, then in my mind you have to be seeing an influx of water main pressure into the boiler system.

I think the upper max for Valiant boilers is around 2.8bar which is considered toward danger level, so I would not be surprised if that has damaged the seals causing your leaks, given you are seeing values of up to 4.5. With regards to the dirt you might want to check they have installed a magnetic filter in the system, as that should catch a lot of the usual metallic debris, and have enough inhibitor added to help stop it being generated in the first place

I was hoping that no one would bring that up as boiler warranties do not cover faults arising from debris from the heating system. 

From the Valliant Warranty Document:

15. If any failure is caused by contaminated water in the boiler (e.g. blockages, or influences of flux residues, iron oxides, limescale, sludge etc.) the engineer’s visit becomes chargeable at the prevailing rates.

The website also states:

Your Vaillant guarantee covers you for the repair of any defects related to the manufacture of your Vaillant appliance. The repair has to be completed by one of our Vaillant Service Engineers and will cover both parts and labour.

Oh dear! I really don’t understand - sorry if I’m missing something but my warranty is with British Gas technically. They have not charged me for any of the parts or Labour even though engineer has said the system is “dirty.” How is anyone meant to know how “dirty” the system is beforehand?! I live in London so probably lots of debris and limescale as well. 

So if someone gets a Vaillant boiler through BG - and a BG engineer does the work does that invalidate the warranty? Does not make any sense 

The installer should have carried out a thorough power flush to remove all sludge and debris from your system. When I had a new boiler installed 5 years ago it took the installer a day and half to power flush 18 radiators. It is possible that the job was not carried out properly and some debris/sludge has now blocked the heat exchanger. I would ask Valliant for an opinion.

Olly_J

LondonS30 said:

Thanks. We did do quite a lot of radiator bleeding before calling BG. We took pressure down to about 1.2. Had to turn boiler off and then on in order for us to read the pressure. Despite bleeding litres from the radiator, when turned back on (without heating or water on), the pressure continued to climb...

Thinking through some more, there should be a pressure blow off valve inside the bottom of the boiler, which triggers at 3 bar, so it could have been this that lead to water coming out as you described originally..Mine has never triggered, but its said that once they do, they are also prone to being clogged with debris, and may never seal again properly, and usually changing them is recommended.

The fact that you have bled litres out of the rads suggests you must be getting incoming fill, as I reduced my pressure a bit after it was flushed, and that let very little water out taking it down half a bar or so...Equally you probably have very dilute inhibitor now