sime super 90 plus boiler intermittent hot water?

super 90 plus works okay but hot water interment .
any one has any advose

raja
May 2011

Yes, definately the "diaphram" within the diverter valve has perished.

bought new one for £18; replaced it and now we have hot water.

Be careful that you don't crack the plastic housing for the microswitch,as then the boiler won't fire when hot water tap is put on.

ZaK Malek
March 2010

Had same problem turned out to be the diaphram in the divert valve,when removed it was badly perished .
Plumber fitted a new diaphram and now works fine.

mick"P"
February 2010

I have just had the same problem. Defect was circlip which holds microswitch block onto diverter valve diaphragm casing had corroded away thus the switch would only make intermittently. Managed a temporary fix using 22 swg stainless wire. I have previously replaced the diverter valve diaphragm (2 years ago) for same problem - the diaphragm rubber was perished. You can see the diverter valve arm operate the microswitch if you turn heating control to summer (off) and have someone run a hot tap. It's a small plunger with a black round plastic cap on it located in the middle of the black plastic block on top of the diverter valve and should rise to make the microswitch when you run a hot tap.this should fire the boiler when working correctly.The microswitch block will rotate freely if you can't see the diaphragm lever arm and you can hear the microswitch click when it makes. BE CAREFUL though, the microswitch is 240 volts so best isolate electricity before rotating the microswitch block!!! If the diaphragm plunger isn't moving, the diapragm itself is probably perished and can be replaced. The microswitch can be tested by manually operating it very carefully with an insulated small screwdriver or similar Good Luck.

Vince
February 2009

The usual problem is the diaphram within the diverter valve. 99% certain if you get hot water when the heating is on.

A Condy
December 2007

common fault on these,100 per cent sticky divertor valve

john wright
November 2007

sticking diverter valve

22
April 2005