British Gas Worcester C1 combi boiler - pressure always high

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We have a British Gas Worcester Bosch C1 combi boiler. When we have the heating on the pressure gauge needle sits at 4, which is the max. It's been off the last few months, but we've had it on and off over the last couple of days. It was switched off at 9am this morning. It is now 3.15pm and the needle is sitting just below 2.

Occasionally my husband has to bleed the radiators upstairs (usually the towel rail one in the bathroom) to get the pressure down, but it soon starts to rise again. He knows he can't do this too often as it is a sealed system. He hasn't touched the silver snake hose (sorry I don't know how else to describe it) that has a screw valve on either end. Is there anything he should do with this instead of bleeding radiators?

For the last 3 or 4 years the BG engineers have always had to recharge it as part of the annual service each April, and they accept this will need done every year. We've also sometimes had to call them out between service visits to have it recharged. During their visits they have always cleaned and adjusted valves and the last time one was replaced, just in case.

We have a small pipe outside which drips constantly when the heating is on. The engineers have told us not to be concerned about the high pressure as it will just give us the dripping pipe, which in itself is nothing to worry about. But surely the whole reason you have a pressure gauge is to keep tabs on the boiler and stop that happening?

Also the last two years the boiler has occasionally failed to ignite when we have run the hot water, usually first thing in the morning and usually following a period of heavy rain. We get a lot of that here! When we press the reset button it fires up no problem. When I question this with any of the BG engineers they say that there could be a host of things that could cause this and, unless they were there at the time this happened, they will never be able to diagnose the cause of this.

The boiler was fitted as part of a new central heating system in June 2000. Whenever I have asked any of the engineers if I should start saving for a new boiler I've always been told no, that it is a good boiler and should do us for at least another 3 or 4 years.

Any advice would be appreciated as I would like to be able to query above points with the BG engineer, rather than just coming across as a daft woman with no technical knowledge (which is true, lol!).
 
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Your expansion vessel is blown and you need a new one. I'm surprised BG haven't picked up on this, maybe it's a pain to change and they can't be bothered...(some of them require you to take the boiler off the wall to change them). Running your system at that pressure is putting extra strain on everything and you should get it fixed. Might be worth dropping BG and getting a reputable local engineer in...
 
Your expansion vessel is blown

Was there any mention of water from the schraeder valve to indicate the vessel diaphragm had ruptured :?:
What about checking the expansion vessel connecting pipework for a blockage?
 
if the vessel has gone and the prv is dripping i think the op would be having to top the pressure up, not let it out! :rolleyes:
sounds more like either the fill loop is passing or the heat exchanger has gone, stick with bg ;)
 
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I'd taken the comment about BG recharging the boiler as recharging the ex vessel, as this appears to require continual attention I guessed that the ex vessel was blown. If I've misinterpreted that's my bad. Either way, it seems BG have failed to fix despite several visits...
 
if the vessel has gone and the prv is dripping i think the op would be having to top the pressure up, not let it out! :rolleyes:
sounds more like either the fill loop is passing or the heat exchanger has gone, stick with bg ;)

No fear of me changing my contract to a local company. I can have as many call outs as I like with BG and no charge for parts. Given the boiler's recent history, if we've got a problem I know I can depend on that. If I took out a Contract with someone else I can only see it costing us far more in the long run.
 
Does the pressure reach 4 bar all the time or only after the heating has been on for a while? if its only after the heating has been on and if they have to constantly recharge it on every ASV and sometimes inbetween then there is a good chance the expansion vessle is faulty or the tube connecting it to the boiler is blocked. get them back and make sure they have a proper look instead of sticking a foot pump on it for 30 seconds.
 
Hoping you can help with new issues detailed in my update below.

Well finally, when the BG guy came at the beg of Dec to do my annual service he agreed that the expansion vessel should be replaced. However his visit coincided with a very cold snap so we agreed to leave things until after New Year. He repressurised the vessel but said this would only tide things over for a short time as it was gubbed. He said he would record this so there would be no problems getting it replaced when I was ready to call them out to do the work. He gave me his name and pay number so that I could give these to the call centre to link them to the job.

The high pressure continued to be a problem until the week before Xmas, when it suddenly dropped to almost zero. I managed to get an engineer's visit for Xmas Eve afternoon. In the intervening days my husband was having to put water in the system about 3 times a day just to stop it from going totally to zero. A different engineer came on Xmas Eve and made some adjustments, but said he didn't have the parts in his van. The same (that's a first!) guy came back 3 days later and said he was sure it was just the pressure relief valve, despite the engineer doing the annual visit's comments about the vessel! He fitted a new one PRV and also a new Schraeder valve, but not a new vessel. He did not check the radiators for bleeding before he left and that evening the top rungs on the towel rail were cold so my husband had to bleed it.

For the next few weeks pressure sat at around 3. Then two weeks ago we woke to what sounded liked a pneumatic drill right beside us as the boiler kicked in at 5.50 am. The whole house shook. We've never had this before. This happened a few more times that morning when we got up and ran the hot water. Then it was fine all day, with pressure fluctuating slightly. The next morning the same thing happened so I called in BG immediately (Friday). They were due to come on the Tuesday but they rescheduled to the Friday. I was terrified that the boiler was going to blow up during this time as every morning we had this terrible noise. However it only now made the noise when the boiler fired up.

A different engineer arrived on the Friday (18th Jan) and wasn't convinced about the noise. He ran a series of tests and relented that it was 'probably' the pressure vessel that needed replaced. He also said some other valves were a bit furred and would get these replaced at the same time. He said that it could also possibly be the heat exchanger that was at fault, but they wouldn't know until the vessel had been replaced. He said he was from outwith our area helping with an unprecedented amount of breakdowns so I knew I wouldn't be seeing him again.

Yet another engineer arrived on the Monday (21st Jan) and worked for 3 1/4 hours to replace the vessel and do the furry valve work. He said the boiler was running fine now and he could see that a new heat exchanger was not required. I got him to check the radiators for bleeding before he left. That evening the pressure started to rise again, but was sitting around 2 1/2, which was an improvement. The next morning we were woken by the terrible noise and it seemed worse than ever. The pressure had also risen to almost 4. We ran hot water to get washed and lo and behold the pressure dropped back a bit.

I called in BG that day and they were due yesterday morning, but called on Wednesday to reschedule the visit to next Tuesday (29th). Since Tuesday (22nd) I have kept a diary of what the pressure was throughout the day, noted whenever I've ran hot water and what the effect this has had on the pressure (generally reducing it). We have kept things at bay by running much more hot water than normal, obviously at an additional cost to ourselves. This morning my husband was up at the loo at 3am and ran hot water then so that we wouldn't have the noise at 5.50am.

It seems to be that the noise will only happen if the boiler pressure is above 3 when it fires up, so we have started running excessive hot water immediately before we go to bed. The boiler goes off at 9pm but the pressure still rises after this, which we can't understand.

Today it is very cold and snow is lying thick on the ground so I turned the heating up a notch from 11 o'clock to 12 noon position at 7am. Prior to doing this the pressure was sitting at just over 2 (having run hot water when we got up at 6 & 6.30 am). At 9.50 am it hasn't changed. I'm about to run some hot water so expect it will drop a wee bit.

Apologies if my post is a bit long winded, but it is such a saga. Does anyone have any enlightening comments?
 
you have already been correctly told what the problem is and I can not understand why BG are messing around either your filling loop is passing (remove the braided hose and if this stops your problems then it was that) or your heat exchanger has pin holed (most likely cause) it is not the expansion vessel or you would have to manually top up the pressure every day
 
Thanks Ianmcd. My husband has said for a while he thought the braided hose could be passing but we were told by the BG guy on the 18th that this was ok. It was the same guy who said if it wasn't the vessel it would the heat exchanger. The vessel was as flat as a pancake.

We have noticed that there has occasionally been noise coming from the radiators, the best I can described it is crunchy water. Don't know if this has any bearing on things.
 
get your over pressurisation problem sorted then worry about noisy rads they may be connected or may not, its not a big job to disconnect the filling loop hose , to be honest it should be disconnected anyway to conform with water By-laws, you will know right away if the filling loop valves are passing as they will leak when you remove the hose, still think you have a heat exchanger problem though
 
As i read through all your issues i was convinced of split vessel however having it replaced and still getting pressure issues filling loop passing would be next thing to check as mentioned above its part of water regs to have the filling loop (silver snake) disconnected after use. If it is not this you could have restrictions/blockages on the system this would cause over heat/noisy rads. The noise you have at 3 bar is the safety valve lifting to stop pressure constantly rising.
 
Thanks guys, I will put your points to the BG engineer when he comes on Tuesday.

Re the hose, are you saying we shouldn't have it at all? Should there be some sort of blanks in place instead? My husband has had to turn one of the screws in it a lot over the last two years to try and keep things at bay between engineer's visits
 
Over the last week I have had four calls about Worcester boilers with excessive pressure followed by virtually no pressure.

One belonging to a friend only six months old ( the boiler Joe, not the friend ) has had BG visit twice.

She called me round and although I will not find out the outcome until Burns Night, all I could find wrong is that BG engineer had put too much air pressure into the EXV.

Tony
 

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