heating problem with vaillant thermocompact

[guyster1973uk]

hi folks i live in a 2bedroom council house which has a vaillant thermocompact heating unit installed( which has worked great in the past). last week the boiler unit started making loud frothing noises and i was struggling to get a decent amount of heat built up so i phoned the council who sent somone out and he said i know what the problem is sir its a partial blockage in the heat exchanger he ordered the new part and fitted it a few days afterwards. after the part was installed im still struggling to get a decent amount of heat built up in the house. i actually noticed when the heating is on the pump is on and the boiler temp gauge idles at 64F the boiler ignites for about 5-10 seconds making a loud whooshing-whistling noise( which was not there before) shooting the temp up to 80-81F then ignition cuts out and boiler temp drops back down to 64F then the boiler reignites and it kept doing this over and over. i phoned the heating engineer back out and explained i couldnt get a decent heat in house and told him about the boiler ignites for 10 seconds cuts out for 10 seconds and reignites over and over again. he said it shouldnt be doing that but never actually checked it( it didnt do it when he was there) and he said as far as i can see theres nothing wrong with your heating. i struggle to get the house temp above 18C and thats with the heating on for 2 hours where as before this fault occured the house temp would get to 22-23C with no problems.

anyone got any ideas about this? the whooshing whistling noise sounds like air or something ive also noticed the heating unit itself gets extremely hot

 

[kevplumb]

any water in the system would be my first starting point

 

[guyster1973uk]

yes theres water in the system it gets topped up once a month by the refill tap under boiler unit and he did it once he fitted new part

 

[kevplumb]

it gets topped up once a month by the refill tap under boiler unit

err

 

[guyster1973uk]

err what? you asked if there was water in the system and i said yes. the water pressure drops a bit every month through evaporation thats why it gets topped up a bit once a month via the inlet tap underneath the boiler

 

[ianniann]

You wouldn't normally need to refill every month, although if it is just a tiny drop each month that may be normal. Are the radiators getting warm in a sensible amount of time? Any cold spots at the top or bottom of radiators?

Call them out again. You and I both know it isn't right. Make a deal about load noises, popping ignition, the boiler case being very hot, try to get their attention.

 

[guyster1973uk]

ive had them out twice this week mate. on both times they came out i explained the problems i was getting with the heating it was basically a case of in 1 ear and out the other. each time the boiler ignites u can hear the whooshing whistling noise in all the radiators quite loudly. they didnt even take the cover off boiler to take a look. ive also noticed as well when the heating is turned off and i go to put the hot water on u can hear the water pumping through radiators dunno if thats normal or not. i thought at first the pump was turned up too high cos no way should the boiler temp shoot from 64F to 81F in 10 seconds then rapidly drop back to 64F

 

[Bunnyman]

Hi mate is it a vc or vu thermocompact approximate age pls it should not go 60 to 80c quick unless flow restriction

Untitled

• Bunnyman
• 26 Mar 2010
• 499

also u don't get evaporation in sealed system u hav a small leak somewhere

 

[guyster1973uk]

there is no vc or vu on the boiler it just says vaillant thermocompact.i moved into the house last year and the person i done a mutual exchange with stayed here for 7 yrs and the current heating system was fitted when she stayed here BUT the heating had never been turned on(mainly due to the fact she didnt bother to get the gas uncapped the whole time she stayed here) i had to get the gas uncapped and i also had to get the heating system commissioned so basically it was a brand new heating system when i moved in so it must be about 5-6 yrs old.im just wondering if some of the debris/sludge that blocked up the heat exchanger has maybe clogged up the pump as well. dont get me wrong the radiators do get hot but the boiler itself gets very hot as well which suggests to me its building up heat on the boiler but its got nowhere to go. the boiler never used to get that hot i used to be able to put my hand on the boiler when the heating was on and it would at the very most very slightly warm sometimes even cold and house temp would be fairly hot.

 

[Homesafe]

Check that the valves under boiler are fully open

 

[guyster1973uk]

checked them they seem to be working ok

 

[Homesafe]

Bunnyman will have this sorted for you , if he comes on.

 

[guyster1973uk]

ok thanks. im gonna phone the council tomorrow and them if they dont get the matter resolved im gonna employ a private contractor out to to resolve the problem and send them the bill for it on the grounds they have been given plenty opportunity to resolve the problem and havent( the last gas engineer didnt even take cover off boiler to have a look ffs). and that im paying rent for a service thats not working properly.

 

[guyster1973uk]

hi folks spoken to vaillant tech support on phone this morning who said they think its a flow restriction/blockage

 

[guyster1973uk]

hi folks got the council back out today( after kicking up a stinker about i cant go another night with virtually no heat) explained to him what it was doing and also told him vaillant tech support said to me its either a flow restriction/blockage or the pump isnt working right. he checked the pump and said its not very responsive its running idle all the time. he fitted a new pump so im gonna see how the heating works now if its still same ill be getting them back out.