Nightmare time with Worcester Bosch repairs

[Cazza]

Hi

Was wandering if anyone can tell me if a competent boiler repair man should be able to detect a leak on an isolation valve to the boiler fairly easily. Worcester Bosch repair men came out 10 weeks ago to repair what was a leaking left flow unit. They also took boiler apart and replaced a few other things just in case that could leak (prv and expansion vessel). To cut a long story short I've had continuing pressure loss since they came out, one bar every 2 weeks. They kept telling me it couldn't be the boiler but I kept running isolation tests which proved to be the boiler. In all they've come out 7 times and 4 times there has been a leak on the left and right isolation valves. They tried tightening one, then replacing both washers, then replacing the right valve and now hopefully they are coming back to replace the left valve which still looks to be leaking.
Their attitude has been horrible, they are now unwilling to come out again they said if there is a continuing pressure loss after their visit today. I've had this worry for 10 weeks, had to run 4 isolation tests, had to take 8 days off work for their all day appointments getting up very early. I don't think I should have had to go through this. They kept telling me I had practically a new boiler so not to worry about the pressure drop. I think they should have ran some sort of isolation test on the second visit to determine where the leak was and properly diagnose it first (on the second visit they actually put in a new heat exchanger instead of finding the valve leak). Can any competent boiler repair man tell me what they think please?

 

[Riley]

Unfortunately, much as we hate it, we live in a society of he who stamps their feet hardest gets things done. I don’t agree with it but such is life

 

[Rob Foster]

Don’t get snarky. I think his point is you need to go higher as was originally said. Arguing the toss with the helpline and engineers who are just there to do a job isn’t going to get you anywhere. Simple fact is yes there could be a leak finishing at the isolation valve however it could be coming from anywhere above. Take what you’ve told us re time off work etc and multiple times where you’ve had to do things yourself and write to the CEO. I’d say for your time wasted they should be contributing to a new boiler or be resolving your issue. Be as blunt as that. They have entered into a contract with you and shouldn’t be allowed to cancel it without penalty

Contractually WB might well be in breach of their contract, especially
as they are actually involved in an on going dispute. Its like saying your car insurance is invalid because you have had a crash. go get them stay cool and WIN . keep us informed get someone else in
pay them and claim it back. ring trading standards you pay rates
Rob Foster aka centralheatking

 

[Rob Foster]

Contractually WB might well be in breach of their contract, especially
as they are actually involved in an on going dispute. Its like saying your car insurance is invalid because you have had a crash. go get them stay cool and WIN . keep us informed get someone else in
pay them and claim it back. ring trading standards you pay rates
Rob Foster aka centralheatking

it would be good to get feed back...thats why we do,this
centralheatking

 

[sammathias]

Vaillant.

 

[Cazza]

Thanks. I've drafted a letter to Martyn Bridges. Worcester Bosch came yesterday and I told him that the left isolation valve is still visibly leaking (even with new washer) and the new right one is also leaking (very strange but a tissue test showed it was). I asked him if he could put some thread seal in the new nut to stop it leaking. He replaced the old leaking left valve and put thread seals in both, he also said he changed a valve or something above the right isolation valve in case it was leaking down onto to it. He also used some joint sealer for pipes or something (can't recall what name he gave me). So he said they won't be leaking anymore (5th time lucky?!). Anyway this morning, before the heating came on, I tested both valves with tissue and they both seem to be dry. I'm hoping this will help the pressure drop problem. Although I'm not sure if it could account for a 0.2 bar pressure drop a week.
If the boiler is finally fixed and this works I will leave it, as they haven't charged me. But if the boiler still seems to be losing a lot of pressure (I may run another isolation test myself if needed) then I will send off the email to Martyn Bridges at Worcester Bosch. Because they should leave me with a working boiler and not a leaking one.

 

[Riley]

Keep in mind that a 0.2 bar pressure drop is not a lot and hence why such a small leak is often undetectable.

 

[John.g]

Thanks for the information. I've got a mixture of plastic and copper pipes. Upstairs where the boiler is mostly plastic. The boiler/ heating had been cold over night before running the isolation test so not cooling down. I thought it strange the boiler and radiator gauges have both dropped at almost the same rate, they are being tested separated with the boiler isolated from the radiators (valves turned to horizontal). Unless the valves leak inside which would explain the same pressure drop.
There is definitely moisture on the boiler valves though, could these account for a 0.15 bar pressure drop?

A 0.15 bar pressure drop isn't IMO just a drop of water from a boiler that's isolated.
If one assumes a 8 litre expansion vessel with a pre pressure of 0.5 bar and a filling (test) pressure of 2.0 bar, then the boiler will lose 0.21 litres of water. If the pre pressure above is 1.0 bar then the boiler will lose 0.28 litres of water for the same 0.15 bar pressure drop.

 

[Cazza]

Yes this is what i've been worried about since as when I asked the last Worcester guy if those tiny valve leaks could have accounted for a 0.15 bar drop in the test he said in his opinion he thinks it could. Which mean't he knew a lot of other people would disagree. Those two valves only had a tiny drop of water on them. The expansion vessel was pressured to 1 bar. The water pressure was put to 2 bar for the test. The weird thing was both the boiler and the radiator gauge fell by 0.15 bar, even though the boiler was isolated. Because I was told 1 bar is like a coffee cup I was thinking 0.15 of a coffee cup is a lot more than a tiny drop with the boiler off (i.e. not evaporating). But everything has been replaced on the boiler that could leak, including the expansion vessel. But like an earlier member said 0.15 bar could be accounted for by a settling down pressure release within the expansion vessel (or within the plastic pipes for the radiators). The only other thing I can possibly think of if they have put in a faulty new heat exchanger or expansion vessel, but that is unlikely. Or is there a leak on my pipes? The Worcester Bosch man did say the isolation tests that i'd been doing weren't reliable because the isolation valves can leak inside so i'm really seeing a drop on my radiator system (but I don't know if he was fobbing me off and I thought his testing with large gauges was supposed to rule that out, hence the whole idea of it)

 

[John.g]

If the Bosch man suspected the boiler isolation valves then surely he could have bled a drop of water off the rads with isolation valves closed, if both pressure gauges then fell together then the isolation valve(s) are passing.
I think that you will have to get someone to rule the boiler in/out, but I can tell you that with a 1 bar pre pressure, and test pressure falling from 2 bar to 1.85 bar that a 6 Litre E.vessel will release 0.21 litres, a 8 litre; 0.28 litres & a 12 litre; 0.42 litres.
In one of your posts you said the pressure was falling 1 bar every 2 weeks, this relates to a leakage (somewhere) of 2.0, 2.67 or 4 litres respectively, boiler or system??.

 

[Cazza]

Thanks John. Yes that is true! He could have tested the isolation valves that way.
After the initial works they did it was dropping a bar every 2 weeks. Several visits later and isolation valves tightened / auto airvent changed/ expansion vessel pressured from 0.4 bar to 1 bar it was more like 0.4 bar drop every 2 weeks or say a bar a month. So something dropped the rate of pressure loss by half. Since he was here 2 days ago the pressure gauge has gone from 1.5 to nearly 1.3. But he did warn me that there would be some air in the boiler so expect an initial loss. Because they say its got to be my pipes just before he left he said I should let it find its only pressure level, and let it go all the way down to 0.5 bar if necessary as that might stop the pipe leak (if there is one). But I don't really want to do that because that will take another 4 weeks and what happens if it drops lower than 0.5 bar then I have a problem. It will be too late to complain to Martyn Bridges by then.
I've turned my boiler off this morning and thinking of running another isolation test for 36 hours on the boiler. As any air should have autovented by now. Also with the two new islation valves I'm guessing they won't leak inside to the radiator pipes.
I will let you know what happens in 36 hours and if the boiler drops. My guess is that it will as I agree around 200ml of water is what must have leaked. But there is no pooling of water under the boiler. So what does that leave that could leak away from the boiler without me seeing? .... prv, expansion vessel or heat exchanger? All of which are new apparently.

 

[Millsy 82]

Every time you do work on a boiler you allow air into the system. If you fully drain a boiler it can take a few weeks for it to settle back down again and get rid of all the air. So a 1.5-1.3 drop the day after they have carried out.

Just leave the boiler alone don't do any isolation tests tissue tests anything for a couple of weeks and let the air settle then look again.

The chances are with everything you say they have done to your boiler it WONT be on your boiler.

 

[Cazza]

Thanks for the information. I'll leave it then for a couple of weeks.

 

[John.g]

If you could shut off the air vent like in this interesting thread it might tell something but you probably can't if the auto vent is inside the boiler casing (not GSR).
Pressure drops when AAV open

 

[Millsy 82]

If you could shut off the air vent like in this interesting thread it might tell something but you probably can't if the auto vent is inside the boiler casing (not GSR).
Pressure drops when AAV open

I wouldn't advise that as it's inside the boiler.

 

[Riley]

If you could shut off the air vent like in this interesting thread it might tell something but you probably can't if the auto vent is inside the boiler casing (not GSR).
Pressure drops when AAV open

Yes please be careful on what you post!

 

[Aire]

A 0.15 bar pressure drop isn't IMO just a drop of water from a boiler that's isolated.
If one assumes a 8 litre expansion vessel with a pre pressure of 0.5 bar and a filling (test) pressure of 2.0 bar, then the boiler will lose 0.21 litres of water. If the pre pressure above is 1.0 bar then the boiler will lose 0.28 litres of water for the same 0.15 bar pressure drop.

Quoting specific amounts of water lost is a little daft given that the amount of water it takes to drop pressure varies more on system volume than the size of the expansion vessel. I know the 2 go hand in hand but the standard vessel within the boiler is good for up to around 100 litres of water. Has op specified how many rads she has? A 5 rad system running at around 50 litres is going to show a much bigger pressure loss with a cup full of water compared to a 10 rad system running at 100 litres. I've had a system where the combi was in the loft in a bungalow, and bleeding a cup full of water out a radiator was enough to drop the pressure to nearly zero. So in my opinion, depending on the size of OPs system, yes a few drops from the isolation valves at the boiler is enough over a week, to drop 0.2bar of pressure.

 

[Cazza]

Thanks for all your thoughts everyone. I have 10 radiators. 4 of them are only a 1.5 foot wide tho. There is a large 4ft one, two 3ft, and three 2ft.
I did not know it takes 2 weeks for any air to vent out of the boiler. That changes everything. Perhaps this was accounting for the pressure loss I saw shortly after the recent repairs, on top of the isolation leaks. No one from Worcester told me this. After they came out the first time it went from 1.5 bar to 0.5 bar within 2 weeks. I doubt that was just air venting. But maybe after they re-pressurised the deflated expansion vessel that fixed that and then any continuing drops in pressure (0.4 bar a week) was just air venting from the boiler. I think i'm going to have to let it settle. If it is still dropping in 2 weeks time then i will run another isolation test. But now I am wondering how reliable isolation tests are if there is auto air venting. I will have to run the test without filling it back up with water (as that would put air back in the boiler)

 

[Cazza]

I forgot to say I only use 5 out of those 10 radiators tho. Keep the other 5 off.

 

[John.g]

I wouldn't advise that as it's inside the boiler.

I did point that out in my post above and IMHO the Bosch service man should have shut off the air vent, stayed around for a few hours and if the pressure increased slightly then vent again.
I spent many years running and maintaining large industrial boilers and various pressure vessels and carried out many pressure tests for leakages, some of these vessels had auto vents but in all cases once all the air was expelled then the auto vents were shut until the pressure test was completed.

Yes please be careful on what you post!

Double post.(above, mine)

 

[J Davies]

I find all the above interesting as someone trying to decide between a WB Highflow 550 and a Viessmann 222F. One installer who quoted for me (and who installs both makes) told me that WB customer service was really good, which was making my decision difficult as for various reasons I prefer the Viessmann boiler over the WB. The comments by Rob F now make me wonder if there is another reason the installer wants me to choose WB and not Viessmann. Perhaps a better profit margin, or maybe Viessmann customer service is worse than WB. Are WB easier to install than Viessmann? Decisions, decisions!

 

[Cazza]

I don't know anything about Viessmann but I was speaking to a boiler service man a year ago and he said he only now installs Valliant boilers as he has had too many problems going wrong with the WB. In my first house I had a Valliant and it was fine (but I was only there 7 years). I don't think i'd get WB again. Although the new WB ones come with a 10 year guarantee, but even still if you can't trust their service men to get to the bottom of any issues what good is their guarantee, just a load of stress.

 

[Millsy 82]

I did point that out in my post above and IMHO the Bosch service man should have shut off the air vent, stayed around for a few hours and if the pressure increased slightly then vent again.
I spent many years running and maintaining large industrial boilers and various pressure vessels and carried out many pressure tests for leakages, some of these vessels had auto vents but in all cases once all the air was expelled then the auto vents were shut until the pressure test was completed.




Double post.(above, mine)

How long do you think they get at each job? They are probably limited to say an hour per job then may have to travel inbetween.

 

[Cazza]

I was told they get two hour slots

 

[Riley]

But I think the point is that not all jobs take two hours and anyone would be naive to think otherwise. That’s not a stab at you cazza im just saying. The expectation and demand on these engineers is sometimes unrealistic

 

[Millsy 82]

I was told they get two hour slots

You will get a 2 hour slot they will have to drive from the last job in that 2 hours if they hit traffic that could affect their time on site.