how can i fix my sime friendly format 80e?

the boiler will run for about 3-4hr then it switch its self off i have to wait about 30-40 min then i have to swich it of alltogether & back on a gane for it to restart
sime friendly format 80 e
s rooke, November 2004


done
i have a friendly format 80E Sime combi.
worked fine til yesterday. Still have gas to the living flame fire in the front room, igniter still seen sparking but no hot water or heat from radiators. pressure is fine and red light comes on to warn no gas is being let thru. Gas engineer told me it was the gas valve, but at a £120 for the part im a bit skeptical. he is charging £190 for the part (£70 mark up on retail price) plus £80 labour so £270 in total. could it not be the gas valve coils?

please help!

P, December 2009
Can i just say don t waste money on buying the whole assembly of the diverter valve, all that should be needed is a diaphragm repair kit for this model, pritty much all heating merchants should be able to supply u with instead of paying 50 for the valve, why not try 15 for the kit? plus u dont need to drain the boiler down if u get the kit all u need to do is turn the cold water inlet to the boiler off and hey presto sorted ;)

Fraser Gomersall, July 2009
I have a SIME Super 90 Mk 1, when switched on at the wall can hear circuit/microswitches kicking in but no power. Checked the pump, and that is working, no hot water at all.

Please help.

Trevor Baker, February 2008
hi i know this boiler inside out i have had all the problems you could think of, after you have done the things that others have said ,then you will find it more likely to be the dry joints on the pcb next to the gas valves,but try the diverter valve repair kit [ pig of a job]if you want, you can check the diverter valve action by getting some one to turn on the hot tap and you look at the mico switch at the back of the diverter valve and you should here a click as they turn the hot water tap on and off, the switch is in the black small box at the back side of the diverter valve diaghragm casing ie 6 small screws around the brass case, if you here this click then the diverter valve is more than likely to be ok this switch when operated works the relays on the pcb to in turn operate the gas valvesto fire up. these cracks on the pcb when warm open up and create this strange mal funcktion of your boiler. bob rob

bobby rob, May 2006
Hello Sime 80E owners I have had the same problem with my boiler not delivering hot water on demand and also no central heating ! both of which were fixed in the short term by switching on and off I have just replaced the divertor valve supplied by ezypart.co.uk cost £48.00 all in delivered to the door next day excellent service and very helpfull with regard to the remedy to the problem.
However the boiler was still not working correctly so have also replaced the microswitch which is activated by the divertor valve on demand for hot water,job done boiler now ok.
another check to do is the ignition electrode gap which should be 4.0 mm with a tollerance of 0.5 mm either way if gap is excessive boiler will not light

Neil Johnson, December 2004
Just happened to mine. Apparently it is due to a divertor valve diaphram failing and will need replacing. Switching the boiler on and off effects a short term solution.

Gordon, December 2004
link Click here to see other fixes for Sime.