Heating problem

[wisey]

HI guys,

Have a Suprima L boiler which is causing me grief at the moment. Comes on in the morning as timed with no problem to heat rads. Seems to turn itself off after about 45mins (presumably has reached temperature) even though heating has not reached setting on room thermostat. Rads then cool down as boiler red light is on and getting no call for heat. Boiler will only come back on if we use hot water. Have recently had diverter valve replaced so don't think it is that.

This is a very intermittent problem as it comes on and off as is should do in the evening.

Any ideas ?

 

[kevplumb]

if it switches on the boiler stat the red light should be on
the green light should be flashing
by divertor valve i assume you mean three way valve (y plan)
did you have the fault before the valve was changed

 

[wisey]

Thanks Kev.

Had the problem of heating only coming on with hot water even when the heating was off on the programmer. Called our plumber mate out and he advised that valve was sticking , we had the same problem last year and he freed it up but this time advised on replacing it so this we did. Heating now works as per the programmer (ie comes on and off at required times) but problem is that boiler heats up in morning and turns itself off (red light comes on) and does not fire up again until called for water heat. This however is not happening in the evening, it will be called for heat by CH as required.

I'm completely bafflled as is my plumber mate so thought I would try you guys for any ideas

 

[kevplumb]

sounds like a wiring fault

 

[wisey]

Thx

Bearing in mind I know nothing about this sort of thing. Does this boiler have one of these PCB's that I keep reading about ?. If so could it be that ?

 

[kevplumb]

wouldnt think so more likley your programmer
as its only happening on a morning

 

[wisey]

Actual programmer as in I need a new one or just the wiring from it ?

 

[kevplumb]

anybodys guess
might be worth getting a spark to check it out

 

[Nemo]

Hi, It sounds like you have a programmer which has more than one time setting, ie morning & evening?

Most have three time settings, morning, midday and evening, most also have a 24hr option.

Have you checked your programmer to be 100% certain that the boiler CH is not on for a shorter period than the HW in the morning?

If the timing is OK, have you tried to run the CH on a 24hr or always on cycle?

As for suspecting the wiring or the programmer... unless there is some mechanical force on the wiring, ie it rubs or is loose then it is unlikely to be the cause of your problem - to test this, try 'beating up' your wiring but VERY gently - give it a slight pul or twist and see if this makes any difference.

 

[kevplumb]

could try resetting it if its digital !!

 

[PEDANTICVINDICTIVEMAN]

I sometimes try the Basil fawlty method, never fixes the problem but I feel a lot better in myself, ahhhhhhhhhhhhhhhhhhhh

 

[ChrisR]

Wisey - when the red light comes on, do you have to press the reset button to get the boiler going again? If so then it's sounding like a pcb fault.

 

[wisey]

No don't have to press reset button does come back on if needed for HW.

If i press for instant CH (ie out of programmed times) the heating comes on fine. This is purely a morning problem in that once it has turned itself off it does not come back on until needed for HW heating. ?

Thanks for all your responses guys - have plumber mate coming out tonight for another look - just wanted some ideas for him as he appears to be at a los as to what problem might be.

 

[ChrisR]

Do you have a mechanical timer - ie with a round clockface type thingy? If so it may be that the first "tappet" isn't doing its thingy. With one person twiddling and another with a meter in the wiring box it would take a minute to check

 

[wisey]

No have an electronic programmer and can set up to 3 time settings ( we have morning lunchtime and evening) lunchtime and evening wor ok.