No hot water

[wudzy]

Hi, I have a Ravenheat RSF 820/20 combi boiler mains fed,
the central heating is working fine no problems there, but my hot water isnt getting hot. when i use to turn on the hot water tap the boiler would fire up, the thermostat would click when turned, but now when i turn on the hot water tap nothing the water is stone cold the boiler dosent fire up and theres no response from the thermostatic knob(which i have changed thinking the thermostat switch had gone)
can anybody help please before i call an engineer and he starts talking spanish to me about it?
thanks,
steve.

 

[racket]

When this happened to a Sime i once owned, the rubber diaphragm that operates the micro switch had perished and needed replacing. There must be a switch in the cold water feed that fires the boiler.

 

[Slugbabydotcom]

can anybody help please before i call an engineer and he starts talking spanish to me about it

More likely he will use Italian. Listen for the word 'Giannoni' followed by the more recognisable 'diaphragm' 'diverter valve' and perhaps 'microswitch'. If he uses the words 'spaghetti' or 'pizza' that probably means that he his hungry and has nothing to do with your boiler

 

[wudzy]

so i take it that its most probably the diverter valve that needs renewing?
any other answers?
thanks

 

[ACOperson]

Yes-a, the diverter or-a micrrosweeetch a needs chaynging peeps.

 

[Slugbabydotcom]

so i take it that its most probably the diverter valve that needs renewing?
any other answers?
thanks

There is a diaphragm within the diverter valve that has probably perished. When a hot tap is opened this diaphragm pushes out a pin which operates the microswitches.
For me it is an on the job decision whether to renew the diaphragm or the full valve as by fitting just the diaphragm I risk leaving a situation where the rest of the valve is at the end of its useful lifespan.

 

[wudzy]

thanks for your help guys, would you say this is an easy job to do myself ive got the cover off and reckon i can swap the diverter valve just 5 nuts and the microswitch, but do i have to drain the whole system down and fully turn off?

 

[Slugbabydotcom]

You should be able to isolate the boiler at the valves underneath. Look for a drain point to get the water out of the boiler usually near the PRV It's a little risky letting the water out of the PRV but if it you do decide to do it that way and the PRV leaks, you can either try opening the valve up and cleaning it or a new one doesn't cost that much

 

[wudzy]

just like to say thanks for all the help on this forum, loads of answers loads of reading, i replaced the diverter valve, everythings working fine now red hot water from my taps again, bit of a struggle tightening up the nuts getting a spanner in there but sorted now.
so thanks again
steve.

 

[uBe_Astard]

just like to say thanks for all the help on this forum, loads of answers loads of reading, i replaced the diverter valve, everythings working fine now red hot water from my taps again, bit of a struggle tightening up the nuts getting a spanner in there but sorted now.
so thanks again
steve.

Same problem here with my Sime super 90 plus. Where do I order parts from and how much did you pay?

 

[Slugbabydotcom]

If you google 'sime diverter valve' You get loads of answers uBe_Astard

 

[uBe_Astard]

Thanks and my part is on order now. Just an after thought however. My boiler would still fire up as if heating the water but it wasnt. Would that still be happening if it is the diverter valve?

 

[Slugbabydotcom]

From a cold start. Turn on the hot tap...... Feel the flow pipe .... That will be getting hot!
It's sending the heat into your heating system rather than using it to heat up tap water.
Replace the full diverter valve ... not just the diaphragm

 

[uBe_Astard]

Thanks very much for your reply. Had a look in there yesterday and decided there isnt much room for my hands and spanners/wrench to manouevre. Decided to pay plumber to come fit it.

 

[uBe_Astard]

I have good reason to believe the plumber who agreed to fit the part tomorrow isnt going to turn up. I wonder if its because I got the part myself and he had to agree fitting it would be about £50 + vat.
Anyway, any tips or pointers as I dont want to be without hot water another day, to do it myself? I am going to drain the system if I do it.
Any help or suggestions will be very gratefully accepted.