Boiler pressure issues. Replaced boiler - need advice

Prothor

looking for advice on what to do, here’s our situation:

• little over 2 weeks ago noticed boiler pressure at 0. Re-pressured the boiler and reported to boiler cover
• Engineer out following day. Replaced pressure release valve
• Next day, pressure still dropping. Boiler cover company advised leave for a couple of days, bleed rads and call back if issue persists
• 2 days later call back as pressure still not holiday
• Engineer out next day (same engineer). Isolated boiler to have hot water but no heating. Said based on outcome, would know if boiler or system was the issue
• Pressure rises to 2.5
• Engineer out next day (different engineer). Said pressure shouldn’t be that high. Lowered it. Said to call back if pressure rises.
• I call next day as pressure is dropping. They ask “is it not rising? Engineer said the issue was high pressure” I told them multiple times I’ve never reported high pressure. My issue is pressure not holding.
• 2 days later another engineer sent (different guy again). This engineer is sent to difficult jobs where previous engineers can’t fix the issue. He takes boiler apart. Replaces pressure release valve again. Tells us there’s lots of sludge, boiler is old (17/18yrs) and that we should look to get a new boiler
• Boiler continues to not hold pressure.
• We get a new boiler, costing 3.5k

it’s now 3 days later and I’ve had to increase the pressure on the new boiler as I woke up to no hot water. It had dropped to 0.7 .

what do I do here? I feel like the boiler cover company have missed something. They said they couldn’t find any leaks but that’s the only other possibility that they mentioned could be the issue. The first engineer said he could put a liquid in to the system that would fill any small leaks (after seeing the result of the isolation test). This was never done, as they sent a different engineer.

I feel as though we have wasted 3.5k and didn’t actually need a new boiler. Where do I go from here? Really appreciate any advice

Ayr_Rage

You need to find the leak in the central heating circuit, it's a pipe, joint or radiator.

mark_cycling00

Hopefully your new boiler will be much more efficient than the old one.

My boiler pressure dropping was due to a rather small leak at a radiator joint.

If you weren't advised to check the things in Ayr_rage post then I don't think you got good advice from the engineers

Prothor

https://forums.moneysavingexpert.com/discussion/comment/81978407#Comment_81978407

engineers checked rads and there were no leaks. One of them said that we would see leaks in the ceilings and walls, but nothing

WIAWSNB

https://forums.moneysavingexpert.com/discussion/6665812/boiler-pressure-issues-replaced-boiler-need-advice

Hi Prothor.

This is a combi? Make and model, please.

I'd give it more than 3 days, as this drop could be down to dissolved air being ejected from the fresh system water. So, take readings, re-top, and monitor. Any subsequent drop should be much less, and then zero. If there's no leak...

Was any reference made to the Expansion Vessel?

A leaking EV can lead to your symptoms. The diaphragm leaks, allowing air into the water side, which is then expelled out the auto air-vent. Result is that the system pressure drops until the EV is empty - this can take a while. And, once empty of air, it'll then lead to pressure increasing symptoms, which - if it hits ~3bar - can expel system water out through the pressure release valve again (even if it hadn't before!).

So, that is one possibility.

The PRV is the go-to cause, but should be accompanied by a check of the EV, and also for signs of water having been ejected out the PRV pipe. Were these checks made - it's usually pretty obvious if system water has been expelled?

Another way pressure can be lost is via the condensate pipe, if the main exchanger has cracked. This can be monitored by checking the output from that pipe, if necessary after adding a tracing chemical to the system water.

If totally stumped on the cause of a repeated and significant pressure drop after this, another test is to isolate the boiler from the rads as they did, but to then - after a day or so - keep a close eye on the pressure gauge as the boiler isolator is reopened - any drop? If so, it implies a leak in the rad system.

Soooo, depending on how thorough they have been to check for the true cause, you may have an argument for claiming that what they did carry out was a bit of a waste as not comprehensive enough before suggesting a new boiler. Let's be frank - a pressure drop has a limited number of causes! (And sludge isn't one of them.)

I would suggest that, at your combi's age, you would likely have been reaching the end of its life in any case, so a replacement was on the cards within a few years? Where this could be annoying is if you were perhaps contemplating an ASHP at some point, but we're trying to hold off for a while - you ain't going ASHP now. But, assuming you were going for a gas boiler next time too, and that this was most likely going to happen within, ooh, 3 years or so, then a new boiler now ain't the worst thing.

But, if they didn't carry out comprehensive tests beforehand, I would expect them to refund the bulk of anything they charged for the initial work. And I would expect them to trace and fix the real cause for free.

Do you have LegProtection in your house insurance? Get your facts succinctly lined up - as you did in your helpful first post - and call them up for advice.

Prothor

https://forums.moneysavingexpert.com/discussion/comment/81978453#Comment_81978453

It was a combi boiler, yes, a baxi. Model was Duotec Combi 24 HE

The last engineer mentioned the expansion vessel but didn’t replace it. He also said he had changed the PRV again as he could feel there was still some water around the washer.

Is the condensate pipe the copper one that sticks out the house? The last engineer who came was the only one who looked for that pipe. He didn’t do anything though, just wanted to know where it was.

The 2nd engineer who came after the isolation only said the pressure was too high and lowered it. He said to call them if it went back up because then it would be a plate that needed to be replaced. When I called them the next day, they said the plate had to be ordered but they were confused why I had called when the pressure hadn’t risen. This is when I had to repeatedly tell them that the pressure rising had never been the issue.

I agree the boiler was definitely nearing the end of its life. It just now feels annoying that we were advised to get a new boiler and that potentially wasn’t even the underlying cause.
What is LegProtection?

Ayr_Rage

What happened with the old boiler is now irrelevant.

You have every right to be peeved that the ongoing cause of the loss of pressure was never identified when the old boiler was in situ.

If the new boiler isn't faulty then you've got a leak in the central heating pipework, once you are certain the system is free of air.

WIAWSNB

https://forums.moneysavingexpert.com/discussion/comment/81978467#Comment_81978467

"The last engineer mentioned the expansion vessel but didn’t replace it. He also said he had changed the PRV again as he could feel there was still some water around the washer." Mentioning it and actually testing it are two different things. Do you know if he did the latter?

"Is the condensate pipe the copper one that sticks out the house? The last engineer who came was the only one who looked for that pipe. He didn’t do anything though, just wanted to know where it was." No, the (smaller) copper pipe is the safety discharge, and is where any system water is ejected once it pushes open the PRV. That should be check number one - is it dripping? Any signs of recent water egress (it should be obvious, as system water has chemicals (and sludge) in it, so some scaly trace is usually left behind once it dries). A small clear plastic bag can be rubber-banded over this to catch the evidence, or lack thereof. They don't appear to have carried out this most fundamental of checks (well, the last guy may have.).

"The 2nd engineer who came after the isolation only said the pressure was too high and lowered it. He said to call them if it went back up because then it would be a plate that needed to be replaced. When I called them the next day, they said the plate had to be ordered but they were confused why I had called when the pressure hadn’t risen. This is when I had to repeatedly tell them that the pressure rising had never been the issue." The 'plate' is likely a Plate-to-Plate or 'Secondary' exchanger, and is the one that provides hot water. If that punctures inside, then mains-pressure water will get into the system water and cause a pressure increase (that happened to my boiler once). Again, not rocket science - isolate the boiler, and if the pressure creeps up, then it's likely to be the P2P.

As Ayr says, the replacement is a fait accompli. But, if you can determine that they didn't carry out due diligence is determining the cause of the issues, and they obviously did not, then why should you pay for a half-completed investigation that cost you £3.5k when most likely not needed?

A new P2P is around £50, or ~£100-odd fitted. (Unless they charge you full RRP.) But far more serious, if there is a leak in the rad system, then 3 guys have been chasing their tails, at your expense, and still not fixed things.

What this means in terms of liability, I don't know, hence mentioning Legal Protection, which should cover you for such issues. In essence, it's a pre-paid solicitor (if you included this - you really should in future), who'll determine whether they haven't fulfilled their expected obligations for the service you paid them for.

Vitor

OP mentioned the first technician isolated the boiler. If they closed the flow and return valves and the pressure held inside the boiler but dropped when the valves were opened, that was 100% proof the leak was in your radiators or underfloor pipework, not the boiler.

FreeBear

https://forums.moneysavingexpert.com/discussion/comment/81978450#Comment_81978450

When I replumbed my CH system (along with a new combi boiler), I found the pressure would drop slightly over the course of a few days. Prior to having the boiler fitted, I had done a hydraulic pressure test of the heating system and found no leaks. No damp patches on any ceiling or floor. In the end, I dosed the system with a leak sealer and not had a problem since.

It may be that you have a tiny pinhole leak somewhere in the pipework. Any water weeping out would probably evaporate before it could cause any staining on the ceiling. In which case, a leak sealer could well cure the problem.

born_again

Put a bit of toilet roll round the joints & each end of the rads. That will soon show any leakage.

We had one end of a rad leaking, but as it dripped onto carpet it dried out & never got as further.