Hot water boiler keeps cutting out

[phil1963]

My water/central heating boiler located in the ground floor kitchen has a cut off switch on it that kicks in if there is a cut in the electricity supply OR if the boiler is close to overheating. When the thermostat is set on the tank in the upstairs bathroom to 40c - no problems but the water that comes out of the shower is not too hot. However when I turn the thermostat up to 50c to get hotter water in the tank and thus in turn my shower I find that the cut off switch kicks in and turns the boiler off totally. So I have to push the reset button on the front of the boiler (a Suprima 60 model) and get the boiler to turn it on again. The question is ...where's the problem??? What's causing it to turn itself off when set at 50C and not 40C?
There is another little dial on the front of the boiler - dies this change the speed at which the water is heated?? Sorry too sound dim - boilers not my strong point!

 

[doitall]

boilers not my strong point!

Not potty's strong point either is the Suprima.

More about how the water gets to the cylinder would be handy.

like;

Size of pipe, Type of motorised valve/s, fully pumped etc[/quote]

 

[phil1963]

Just to confirm - the boiler comes on okay and heats the water at 5am and then goes off at 6.30am. However it often fails on its evening run from 5.30pm-10.30pm which is a bit spooky. Is there a loose connection type thing??
Phil

 

[bathjobby]

There is another little dial on the front of the boiler - dies this change the speed at which the water is heated??

This determines how long the boiler fires for so therefore the higher the setting (usually 0 (off) to 6) the longer and hotter the boiler will run in getting your hot water in the tank to the selected temp. N.B. Tank therm is normally set to 55c or 60c, so you are way below this. If you have the boiler set on high then chances are the safety cutout (reset) is operating first; my Potterton does this if turned up high. Consensus (on this forum in the past) is that Pottertons suffer this if boiler setting on anything more than about 4. I have my tank on 55C and have turned boiler down to 3.5 and all is well. It means the boiler cuts in and out more (rather than fewer longer burns) when running, but at least it runs.
This all assumes your systems is clean and has no air locks and its just your boiler on a +4 setting......

 

[phil1963]

The boiler came on at 5.30pm and it cut off at 6pm - it was set on the 4th lowest dot of 14 on the dial which has dots and not numbers - what's wrong with the thing ? Why does it keep cutting out??

 

[Baxi-Remeha]

do a search on suprima PCB

 

[gazthepottertonengineer]

me thinks its 99% certain it needs the new suprima pcb kit part nos 5111603 to be fitted by a corgi registered person i might add

oh Jason met your friend Stacie earlier training on the new k/fisher HE

 

[phil1963]

Cheers for that Gaz - out of interest what it is that I am after - what does that parts number actually relate to??

 

[gazthepottertonengineer]

pcb kit basically replaces pcb and complete wiring harness