combi boiler pressure, noise; please help

[redwellies]

Hi everyone. I hope you can help a clueless soul like me!

I paid a fortune last week to have my combi boiler serviced. Pressure was reset to 1.26 bar and a safety valve was replaced. In the week since, the pressure rose to 2+ cold and almost 3 until I switched it off.

Rang the company that serviced it and was told to lower pressure by bleeding radiators. Have just done that, to about 1.2 bar, switched it on, and heard the most almighty rattling/clumping noises. Switched it off and called company. The man's going to have another look. Is there anything I should know, or is it probably ok?

And, for next time, how much should I have to pay for a combi boiler to be serviced?

Other Q & A's on here have really helped since the initial call out. Any answers you can offer now would be much appreciated.

Thank you!

[buildersmate]

No, its not OK and you should be asserting that something has been done in the service that has fouled things up - unless they can show you otherwise. It's too much of a coincidence.
Perhaps Gucciman can advise on your other question, but I'd have thought �60-�80 for the service plus the cost of any parts replaced.

[gucciman]

firstly, when you had your boiler serviced you say they replaced your safety valve, presuming you mean your pressure relief safety valve (prv) why was it replaced? were you having problems with the boiler? had the pressure guage been rising or dropping to zero or both, and had the overflow pipe on the outside wall at the back of the boiler been dripping?

since the service, when the pressure rose was that with the boiler running or overnight when the boiler was off? how quickly did the pressure rise?


its hard to say what the noises could be without examining the boiler, the only moving parts in the boiler are the fan and pump, could be one of those making a noise or it could possibly be the boiler actually boiling the water inside the heat exchanger for some reason (boilers arent actually meant to boil the water)

your heating engineer should definately return to put the boiler right.

as for a service, we only charge �40 for a basic service but we do tend to be the cheapest around (which is why we are always fully booked and never short of work) the average price seems to be �60 to �70, i believe british gas currently charge �79.

[redwellies]

Thank you both.

There did seem to be something wrong with the boiler, although hadn't looked at it before that. Didn't know how it was meant to work or the signs of anything not being right.The overflow was leaking and isn't now. Either the guy failed to spot an existing problem, or caused one, but as I paid for the thing to be serviced (rather than fix a specific fault) I think the company's job is to sort it out.

The noise has stopped now, but the pressure's not right. Pressure increases when it gets hot (by about 0.5 bar) but then doesn't settle back to where it was when it cools down (generally 0.2 bar higher). If it's increasing overnight, it can only be by a very slight amount. The guy's coming out to have another look, and I don't want to let him go until it is actually, definitely, fixed.

Thanks, I think I'm more equipped to know whether it's working properly now, and when to call the company back until it's right.

[buildersmate]

Pressure does increase between hot and cool situations and 0.5 bar difference is typical. This happens because water (and gas for that matter) expands a bit when heated.
But (obviously) the volume returns the the same volume it occupied before as cooling down occurs. So something else is letting either more water in, or air in, or hydrogen gas is forming as a byproduct of slight sludging processes. It's a fundamantal principle of physics that the extra water/gas that it causing the extra pressure came from somewhere external.

[gucciman]

builders mate is right in what he says about water expanding
but your pressure guage will jump 0.5 of a bar as soon as you turn the boiler on because of the pump pressure.

from what you have said and in particular the dripping overflow pipe i suspect that you have a problem with your expansion vessel. the expansion vessel is hidden at the back of the boiler and is pressurised with approx 0.7 bar of air. i would check the level of air in the expansion vessel and pump air into it if needed. if when checking the air level any water comes out of the car tyre type valve on the expansion vesel then the vessel needs to be replaced. (these are jobs for the engineer as you need to know how to do it properly i.e. you aways check the air in an expansion vessel with the boiler drained of water)

if its not the expansion vessel at fault then it could be that your filling loop is not shutting off properly and is passing small amounts of water continuously into the system, easily checked for by unscrewing the loop and making sure no waters still flowing.

lastly it could be the secondary heat exchanger at fault and its leakng mains cold water into the heating circuit, a very rare problem though, only seen 1 in the last 2 years.

out of interest how much did you pay to have the boiler serviced?

and please let us know what happens as i always like to know.

[redwellies]

Thank's again all. As an update here's the email I've sent. The company's name etc are changed:

Dear Fastbuck,

This job has been an expensive and miserable failure. It has been stressful and time consuming.

My combi boiler was serviced on 08/01/09. A safety valve was replaced and the pressure was reset. This cost �312.41 and a day's holiday from work.

Within days [ .... ] but it didn't work.

The engineer called again yesterday and found that a pipe had been connected to allow water into the heating system, and it was letting in water slowly but continuously.

He told me that he had disconnected it. I know he has disconnected it because there's water on the floor behind my fridge, leaking from the disconnected points on the mains and heating sides. It may not be his fault that they're leaking but he should not have left the job without checking that it was completed properly. It didn't occur to me that pipes would be disconnected without being sealed properly, or that the flexible pipe would be left propped up against another pipe and left open, holding water.

[continues...]

[redwellies]

[ continued]

I have been told that this can be repaired at the normal (high) half-hourly rate, plus materials, plus VAT. If this was being done as part of the first visit, as a result of the service being thorough and work being properly checked, this might be ok. I do not think it is appropriate when the work has to be done on a third visit because the original service (isn't a service meant to be thorough, isn't that the point of them compared to, let's say, a repair?) and the call back visit failed to be completed properly. On the call back visit I asked if it might leak, if it would all be ok, and was told it would be fine. Because the pipes are behind the fridge, this could have gone on longer and been more of a problem. It's just as well that, after the original service, I had serious doubts.

Please respond by email with a solution. The solution must not involve the original engineer as I would rather the work be carried out by someone who will check it afterwards. It must not cost me any more money (unless you also plan to reimburse me for the time I've spent bleeding radiators, making phone calls, mopping up water and waiting around; at least 3 hours at �47.50 per half hour, VAT free (bargain!!)). It must be prompt [etc]

Regards
Redwellies

[redwellies]

Please can anyone help with the latest development?

I'm fuming, just had this email back from THEM. Has anyone here had any success in complaining about poor customer service?

Dear Redwellies
I have investigated the situation and spoken to the engineer who carried out the work, he assures me that the pipe was not leaking when he left it, he knows this because he dried the pipe with a tissue and spent some time checking and re checking it before leaving, this means he has done his job correctly. If the pipe then develops a leak over the coming hours/days means there is a fresh fault with the valve that was not present or evident at the time, our engineer can not be expected to fix a leak that does not show itself when he repeatedly checks it, any further visit to the property to rectify a subsequent leak would be chargeable as he advised you, this is not unreasonable and considering the boiler was working fine when he left with no sign of any air or noise in the system and no leaks whatsoever means we are not able to carry out any further work without charge. Our engineer has been more than helpful throughout in giving you advice over the phone and then coming out again free of charge to carry out more work to stop the system over pressurising.

You have now had someone else work on the system and although you may claim that they have not caused this latest problem, the fact that they were the last to work on the system means they are more likely to be held responsible than our engineer who left the system working perfectly.

Regards
Fastbuck