Combi boiler losing pressure

[terryplumb]

You may have heating pipes buried in the concrete. If you look at the pipework going to each ground floor radiator ,it may give you some clues . Do pipes come up vertically from concrete to radiators ,showing some pics would be useful.
As boiler is on the ground floor ,some heating pipes from boiler must rise up to rads on higher floors,and would run between upstairs flooring and ground floor ceilings.
The pic of your boiler shows the heating pipes heading downwards from the boiler ,can you see where they go to ?

 

[TonerG1995]

You may have heating pipes buried in the concrete. If you look at the pipework going to each ground floor radiator ,it may give you some clues . Do pipes come up vertically from concrete to radiators ,showing some pics would be useful.
As boiler is on the ground floor ,some heating pipes from boiler must rise up to rads on higher floors,and would run between upstairs flooring and ground floor ceilings.

The pipes do all come up vertically from concrete to the radiators!

Interesting…thank you for that. So it could well be a case of a plumber breaking into the concrete on the ground floor or taking up the floorboards upstairs? That’s well beyond my level of expertise!

I’m guessing there is nothing I can do to pinpoint the leak (if there is one!) without being fairly invasive?

I guess if there was a leak upstairs, it eventually would’ve found its way through a ceiling?!

 

[terryplumb]

I guess if there was a leak upstairs, it eventually would’ve found its way through a ceiling?

Very likely it would.
Pipes buried in concrete , ( especially copper pipes) if they develop a leak can go undetected and are often difficult to pin point exactly where the leak is.
It's often better to run new pipework ( not buried) rather than dig up concrete.

 

[TonerG1995]

Very likely it would.
Pipes buried in concrete , ( especially copper pipes) if they develop a leak can go undetected and are often difficult to pin point exactly where the leak is.
It's often better to run new pipework ( not buried) rather than dig up concrete.

Great - thank you!

I’ll get the council on it as it’s definitely way beyond my remit.

In the interim, is topping up my boiler once a fortnight (roughly) going to do any extensive damage to it? It took the council three months to replace a radiator so I don’t see this being a quick fix!

 

[terryplumb]

Before you had a combi boiler installed ,and a pressurised / sealed system ,what type of boiler did you have ,and was it fed from a small tank in the loft ??
Constantly introducing fresh water into the system will eventually weaken the inhibitor content and promote corrosion. You should get on their case daily !

 

[TonerG1995]

Before you had a combi boiler installed ,and a pressurised / sealed system ,what type of boiler did you have ,and was it fed from a small tank in the loft ??
Constantly introducing fresh water into the system will eventually weaken the inhibitor content and promote corrosion. You should get on their case daily !

Before the boiler was installed, we had a massive copper cylinder in a cupboard and a tank in the loft, it would take about an hour to heat up before anyone could have a bath and longer if there were radiators on! It must’ve been ancient as the guys removing it were shocked to see it. I would imagine the pipes must be equally old.

The boiler has been a nightmare since it was installed. It blew through a radiator and it’s clearly done for another pipe somewhere in the house!

I’ll call them again after new years and report it. We had somebody come a month or so ago as the boiler was faulting out (the condensate pipe was blocked). I explained the constant boiler pressure drop off and he said it’s likely a tiny hairline fracture in one of the pipes but stopped short of reporting it or helping to fix it!

 

[TonerG1995]

Evening guys,

Just a little update - or not - I put a bag over the pressure relief pipe a little while ago and it’s bone dry, despite all the rain and wind we’ve had!

I spoke to the council and they’ve lodged a repair, however this will most likely take months to happen.

I was just wondering if anyone could shed some light on the type of leak I could be having…When I first posted this thread a week ago today, the pressure was around 1.1 bar. This evening the pressure is at roughly 0.8 bar. So we’re looking at a 0.3 difference in a week…would this signify a huge leak, or possibly a small one that could be evaporating somewhere?

I’m almost certain it’s under the concrete on my ground floor, but it’d be good to know if it’s flooding the floor underneath, or just dripping/dripping and evaporating.

Many thanks!

 

[terryplumb]

You have a small weep somewhere. It doesn't take much to drop that amount over a week .

 

[TonerG1995]

You have a small weep somewhere. It doesn't take much to drop that amount over a week .

Thanks for this! So long as there isn’t a huge amount of water being dumped into my foundation, I can afford the council some patience!

I’ve looked pretty much everywhere. It’s not any of the radiators and I’ve checked all the exposed pipes.

Good luck to the poor guy who has the task of finding it…I’d like to think they have thermal cameras to help them, rather than picking a room and hoping for the best?!

 

[Ltnman]

Time to add some https://fernox.com/product/leak-sealer-f4-500ml/.

 

[TonerG1995]

Time to add some https://fernox.com/product/leak-sealer-f4-500ml/.

This is very interesting! Is it easy to apply?

 

[terryplumb]

You shouldn't add any chemical leak sealer to your system ,and if you are a tenant,you shouldn't do anything else to the boiler or heating system either.

 

[TonerG1995]

You shouldn't add any chemical leak sealer to your system ,and if you are a tenant,you shouldn't do anything else to the boiler or heating system either.

To be honest, I wouldn’t have the first clue how to anyway! I’m just surprised such a product exists!

 

[Ltnman]

The product works and can save hundreds of pounds in tracing a leak. https://www.screwfix.com/p/fernox-f4-central-heating-leak-sealer-500ml/766pp and read the reviews.