potterton flamingo 20-30 overheats when on C/H , fine on H/W

[san04]

Hi Guys,

Potterton flamingo 20-30 is fine on H/W but appears to be overheating when on C/H. After about 45mins of C/H boiler shuts itself down and pilot light would go off. I have to press the reset button to re-ignite pilot light and would fire up again without any problems. Since it happens only on C/H my first thought was may be there is blockage in C/H but i've checked all Radiators and appears to be warming up ok. Any help would be appreciated.

Thanks in advance!

 

[45yearsagasman]

Are you sure? Don't remember those old boilers having overheat protection.

 

[san04]

Sorry just re-read its actually RS 35-50

 

[Agile]

Sounds like a failed/failing pump.

See the FAQ on checking your pump.

Tony

 

[DP]

Tony, why failed pump? With dicky pump, surely circulation to gravity HW (I am assuming this is what is in place) would not O/H boiler. If fully pumped CH+ HW, failed pump would O/H boiler during HW demand. Or am I talking rubbish

 

[45yearsagasman]

san04, you don't say how your system is configured, ie fully pumped using a motorised valve, or pumped heating with gravity circulation to the cylinder. If the latter there will be 2 x 28mm pipes plus the heating circuit connected to your boiler.

 

[san04]

it has Drayton motorised valve and there is a pump to one of the , think its fully pumped using a motorised valve ??

 

[san04]

it has Drayton motorised valve and there is a pump to one of the pipe*, think its fully pumped using a motorised valve ??

 

[45yearsagasman]

Post a pic of the pipe connections to the boiler and the pipes and valves in the airing cupboard.

 

[Agile]

Tony, why failed pump? With dicky pump, surely circulation to gravity HW (I am assuming this is what is in place) would not O/H boiler. If fully pumped CH+ HW, failed pump would O/H boiler during HW demand. Or am I talking rubbish

We dont know how the system is configured ( yet ).

I dont assume what the HW is. Even gravity often has a Drayton or Clytrol non electrical control.

If it was fully pumped and the pump failed then if the HW circuit was open that will often create enough gravity circulation to prevent the boiler from overheating.

I still expect its a pump problem but it could also just be sludge blockages.

These are crosswords without clues!

Tony

 

[DP]

OP, is the motorised vave 2 port or does it have three connections on it? Can you get CH WITHOUT HW coming on? There will be two pipes connected to side of the cylinder. Do either of these pipes have a contraption fitted with a thin wire going to a doofer clamped to the cylinder.

 

[san04]

Its a 3 port valve, Yes CH comes on without HW or vice versa. However this morning i've noticed when on CH only there was hot water dripping from a overflow pipe (outside near roof edge which appears to be coming from roof tanks??) and it stopped as soon as i shut the CH down. Any ideas?

Here attached pic from airing cupboard.

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