Bubbling hot water pipes - have changed thermostat

[Rotondo]

Hi all,

i have a potterton suprema 40l boiler with potterton timer control and Drayton hot water thermostat.

a couple of weeks ago, I noticed the hot water cylinder and surrounding pipes which are in my bedroom were making a really loud bubbling / gushing noise. Initially I thought it was the radiator system so bled those, and called out an engineer with my emergency home cover.

They replaced the wiring box and said that was the problem. A day later the noise came back.

i know nothing about heating systems and my neighbour said that if it happens when the hot water is on (but not the heating) it must be something to do with the hot water system and to turn the temp down. It was on 60 so I reduced it to 50 and it was still boiling in the pipes. I called out the engineers again who thought the cylinder thermostat might be bust, so they replaced this yesterday. I had it set to 50 but apparently the temp was 70.

anyway today when the hot water timer kicked in, the bubbling and gushing noise started again. The boiler downstairs seems to keep on triggering even when the hot water is boiling. The thermostat is pressed firmly against the cylinder.

my pot of claims money has run dry, so I will need to fork out for this myself, does anyone have any ideas what might cause the water temp to keep rising even with a new thermostat?

BTW the boiler was serviced a couple of months ago and the PCB was replaced 9 months ago.

thanks for any suggestions.

 

[secret squirrel]

First of all,

How can your pot of money run out when the problem has not been resolved?

Phone the muppets back and shout at them, they have replaced components and not resolved the problem.

It maybe the boiler overheat stat that is not cutting telling the boiler to turn off, this would explain the boiling, if the water were being thrown around the rads as well the problem wouldn't be as bad.

My first point of call would be get the muppets back, make sure the one turning up is GSR so he/she can test the boiler.

 

[secret squirrel]

Just because a boiler has been serviced does not mean that it cannot develop a fault, this can happen as the engineer leaves the house......

 

[SimonG]

How does your pot of claims money run out when they haven't fixed the problem. Get them told to get their backsides out and fix the problem as it's still the original issue.

 

[secret squirrel]

How does your pot of claims money run out when they haven't fixed the problem. Get them told to get their backsides out and fix the problem as it's still the original issue.

Toooo slow mate, great minds think alike

 

[Rotondo]

Thanks guys, sounds like I am being fobbed off then, apparently my 'insured incident total' is £500 inc vat, but in any case yes I'm probably being too soft on them and even though they've spent almost 4 hours labour and have replaced a thermostat and wire box, this is true - the original problem is not fixed!!

im a bit surprised the engineer didn't check other related components that could cause this, at first he too thought it was the radiator system and spent an hour looking for the central heating pump which he never located, then said he wouldn't go up in the loft as there was insulation on the floor and he couldn't be sure he wouldn't fall down through the ceiling. It was only on his third call out and after I spoke to a neighbour that he agreed the bubbling noise might be a faulty water cylinder thermostat so changed it anyway as he had one on the van and said it should be resolved.

i don't want to look like I am grassing this guy up, but I don't really want them to send the same guy out, he didn't seem thorough enough.

 

[galaxy_plumbing]

by chance, is not your immersion on?

 

[Rotondo]

Hi, no my immersion isn't actually wired in, it's in the top of the tank with no wires attached!

Could it possibly be the control timer unit if its not the boiler thermostat?

 

[jtsplumbing]

what about a faulty diverter valve stuck open and calling for heat ?

 

[Rotondo]

what about a faulty diverter valve stuck open and calling for heat ?

Is this the 3 port valve?

they checked this, originally the engineer said it was stuck in the mid position, but when he came back with the parts to install he took the motor head off and said it was moving freely and did some tests on it, all seems ok. When I switched the thermostat down to 30 to cool the tank then switched it back up again, the boiler kicked in and the level on the value moved across.

 

[jtsplumbing]

call them back in ! you are paying for a service, been out and not sorted it , it sounds like a control problem and not the boiler, maybe wired the cylinder stat wrong.

 

[Rotondo]

call them back in ! you are paying for a service, been out and not sorted it , it sounds like a control problem and not the boiler, maybe wired the cylinder stat wrong.

You are so right!

I'll be honest I was planning to give up and get my own heating engineer work done out of the insurance, but after speaking to one today (who previously fitted my PCB), they were talking about all sorts of stuff from re-wiring my heating, putting in wireless systems, sending 2 engineers instead of 1 etc and it was all beginning to sound expensive - I was quoted £200 for 2 engineers to come out to do an hours worth of checking of the wiring.

so at that point I remembered what you guys have been telling me in this thread, and yes, why should I pay for this myself?!

so I rang back nationwide home emergency who were very apologetic and said a third call out was unacceptable, and they have requested a different engineer attend tomorrow.

so fingers crossed!

thanks guys, I'll update in due course.

 

[Rotondo]

Thanks everyone, and well done to secret squirrel who guessed correctly, the boiler stat had no current and was busted.

i rang back the insurance company as suggested yesterday and asked for a different engineer (the last guy came round three times and didn't fix it) and this guy found the fault within 5 minutes.

so they will be back to fit the part in the next few days and fingers crossed I should hear no more bubbling!

would I still need to bleed the cylinder / radiators to get rid of any air in the pipes due to the water boiling or does it not work like this?

 

[ambrosia]

so come on Rotondo tell us what did he find and what was the part he's replacing

you cant leave it a mystery

 

[snowhead]

"so come on Rotondo tell us what did he find and what was the part he's replacing"

the boiler stat had no current and was busted.

 

[Rotondo]

Yes he found the fault with the boiler stat pretty quickly which was good.

They will be out to replace it Tuesday or Wednesday.

however yesterday as an experiment I drained all the hot water from the cylinder and switched everything off, so the tank was cold. I then switched on the system and hot water, and the bubbling gurgling noise from the cylinder kicked in straight away (not as loud as normal). I thought this was just happening on a hot tank so told the engineer. In any case he's found the busted thermostat in the boiler so lets see if that fixes the problem .