Heating comes on when not on demand/

[krishenacharia]

Recently I hadall my underground central heating pipes replaced with new over ground pipes.Radiators with thermostatic valves were also replaced at the same time at ahuge cost by British Gas. I have a Worcester Bosch Combi Boiler Model 37ICC2also installed by British Gas 10 years ago.
Since warmer days it was noticed that heating was coming on when not demandedby the thermostat sometimes temperatures reaching 23 degrees centigrade.British Gas engineers have made five visits changing the thermostat on the wallwith a wireless one but the problem continues and would seem to be of noimportance to British Gas.
Can any forum member help suggest the cause of this problem and solution.
Prior to the change of pipes we never had this problem and of the report pipeshad to be changed because British Gas fixed a UNSAFE notice on the boiler andgave me a copy. For my own and safety of my family as well as keeping thevalidity of building and contents insurance I had to get this work done.

 

[stokecity]

what exactly does this notice say?

 

[JAP&H]

How can re-routing a few flow and returns to rads solve the problem of an unsafe appliance? Something not right.

Last time I attended a "heating on when not required" it was moisture getting to PCB. The ones prior to that had been incorrectly wired room stats.

 

[krishenacharia]

How can re-routing a few flow and returns to rads solve the problem of an unsafe appliance? Something not right.

Last time I attended a "heating on when not required" it was moisture getting to PCB. The ones prior to that had been incorrectly wired room stats.

"It was entire pipe work changed not just few radiators. New pipes are laid in the loft and drop to each or pair of radiators in the rooms. It is a bungalow so it was easy. I reproduce what the negineers have done over five vists and what they suspected. Please give me some further advice and I thank you very much for your help.
POSSIBLE CAUSES SUGGESTED AND ACTION TAKEN BY BRITISH GASENGINEERS.
1. If the boiler is set to ECO i.e. not to preheat water theboiler works OK. 22/5/12
2. Thermostat wiring inaccurately wired in the box above theboiler.
3. Thermostat wiring faulty.
4. Hot water valve in the boiler could be split spillingsome hot water in the heating side.
a) Changedthe thermostat with the wireless one and left the setting as set by factory.
b) Boilerfrost protection was set to 30 degree centigrade reduced to 10 degrees and thiswill stop the heating coming on. 28/5/12
c) Thetimer in the boiler deactivated as it may be in conflict with thethermostat/timer in the hall way.29/5/12
d) Resetall boiler parameters. 30/5/12 PM(British Gas Engineer)
e) Noheating. Thermostat set to 23.5 manually (Display 21.5) Flame symbol on display.31/5/12.
f) TurnedON boiler Timer and set the room thermostat to 21 degrees all day and 18degrees at night. 1/6/12 10:45 AM "

 

[krishenacharia]

Thanks for quick response.The notice stated the boiler and the system is UNSAFE and danger to life andproperty thus should not be used. Reason could not test at hightemperature-flow restrictions.
Look for further help which is very much appreciated and gratefully acknowledged

 

[SimonG]

Frost stat was set to 30 and now reduced to 10 (still too high), where is boiler located?

 

[JAP&H]

c) The timer in the boiler deactivated as it may be in conflict with thethermostat/timer in the hall way.29/5/12

f) Turned On boiler Timer and set the room thermostat to 21 degrees all day and 18degrees at night. 1/6/12 10:45 AM "

First of all it doesn't look as though BG blokes communicating with each other.

I take it the frost stat is in the loft, would suggest this is possible cause of nuisance firing if boiler/system was ok prior to fitting.

Was a pipe stat also fitted?

 

[joe brown]

Turn eco button off, check frost stat temprature and see if the pipe stat isnt defected then ur problem will be solved, its the eco button activating thats causingthe eratic behaviour !! coupled with wrong temprature settings and either no pipe stat or faulty pipe stat... in my opinion only

 

[Millsy 82]

Do any of the pipes get hot under the boiler when you run a bath sounds like duff DV

Why did you have to have pipework changed I cant think of any reason why you boiler would be at risk due to heating pipework.

 

[JAP&H]

Why did you have to have pipework changed I cant think of any reason why you boiler would be at risk due to heating pipework.

Wise words Millsy.

 

[desrob]

frost stat should be at 5degrees max,and i go with joe browm no pipe stat.seen this before

 

[stevetheplumber]

i recon you need a powerflush:cowboy:

 

[krishenacharia]

i recon you need a powerflush:cowboy:

Thanks to allkind persons responding to my problem.
The boiler is situated in the garage which is part of the bungalow sharing twowalls with two bed rooms.
The new pipe work was fitted in late December 2011 and as per British Gas thesystem was cleaned/flushed with a suitable central heating fluid and filledwith inhibitor. In addition to all new pipes all old radiators (7) and electrictowel rail was changed. Total cost was £4000.00. I am quite confident that thesystem was not flushed as it was all done hurry in the last daybecause of Christmas, three radiators were left shut and pipe leaking from theloft. A magna filter was fitted in the boiler and one of the engineers remarkedthis filter is sufficient to keep the system clean. The annual service wascarried out in May this year and the boiler is being serviced and maintained byBritish Gas since installation as was the old system since 1985 when we movedin, the property being built in 1984. Until the boiler change we had no problemwith the heating or the pipe work. I am not even sure of the pipe work?
Is there any heating specialist consultant who could look at the system onpayment of a fee? I live in Milton Keynes.
Any help and advice will be appreciated.