sime boiler knocking off

[worf]

perplexed.......

I have a Sime Friendly Format 80 e.

Water, both heating and hot water supply, will only run for a given period before the boiler knocks off; It will sound almost as if it is runnig, but when you check the glass there is no burner flame. The running time can last from ten minutes to half an hour sometimes, then it runs cold. The boiler then has to be turned off for a few seconds, then re started. Can anyone help?

 

[unclestoo]

Hi, once the boiler "knocks off" what colour are the status lights on the boiler?? Are they flashing??

Stoo

 

[ChrisR]

Blocked secondary heat exchanger would be short odds.

 

[Agile]

No, he says it runs on heating or DHW for 10-30 minutes.

The fan on those boilers get quite hot and often seize or it could be the venturi or APS. Although its odd that he says that he has to switch off first as that would point to an electronic control problem.

Job for a CORGI probably.

Tony Glazier

 

[worf]

Thanks for the replies guys.........

Stoo ... the light remains on green and appears as normal.

I don't tend to touch boilers; indeed, as suggested, I have a newly qualified Corgi reg'd friend trying to help me with this problem. His mainstay is in the repair and installation of systems while another chap in the company does the fault finding.

This has had a couple of guys guessing, one suggestion being the board requiring replacing. I had also wondered about the functionality of the thermistors, although I'm tending to lean away from this one a bit.

As Tony says, it does look like an electronic problem somewhere; the diagnosis of the board may be correct. However, I want to find out as much as poss before I go and fork out around eighty quid for a board.

Dave

 

[Tinitus]

Hi I have changed a few ignition boards on this boiler and I think it sounds similar. The board I am meaning is attached to the gas valve and you can sometimes smell it burning. The fault occurs now and again but never when you are trying to find it.

Good luck!

 

[unclestoo]

Strange you have to restart the boiler, so i have to agree with Agile that it would point to the PCB. Have the same boiler myself, sounds nothing similar i've had to contend with!!

Looking at the fault chart though, given what you've said, first call is replace the C.H thermistor then the PCB. Your call!! Tend to lean the other way on the thermistor approach, i.e pennies verus pounds

Best of luck,

Stoo

 

[Agile]

You can check the thermister with a meter.

Unlikely to be that causing a need to reset.

Tony

 

[Terry B]

If you have to turn the boiler off and on again to get it to work, the problem is with the ignition box(fixed to the gas valve).
It most likly is a royal blue colour and will require changing.
the part number is 6210203 (note some later boiler have a turquoise colour box they cannot be interchanged, the number for this box is 6210205)
Ring Sime on 08979911114 for a supplier or service agent.

 

[bobcratchet]

I have exactlly the same problem with my sime friendly format E
what was the solution to the problem in the end?

 

[MattSalmon]

I have the same problem - boiler fires, runs for approx. 10 minutes then goes out. Have to switch off and then on again to restart. Thermistors have been replaced. Do I need to order PCB or ignition box to rectify problem?

 

[penfold46]

This thread is 5 years old.

 

[Agile]

You need a competent boiler engineer who is not frightened of Sime boilers.

Tony