Ravenheat RSF 84 Problems

[alanry]

Hello, all
When I select hot water, the radiators get warm as well. I suspect the diverter valve as being the culprit. Also, when the CH is off, the HW is barely tepid, but piping hot when the CH is on. Could this also be due to the Diverter Valve? The other problem I have is that sometimes the CH does not work. The burner shut off before it reaches full temperature as set by the heating stat. Howevr, if I run the HW, it will eventually warm up and the heating work properly when I turn off the hot water tap.
so fat I have had two engineers out to it:
1. Suspected pressure switch. Changed it, no difference, so refitted original at no cost for parts. Otherwise stumped.
2. Cleaned pilot jet. Said if this didn`t fix it, then I would need a new ignition board. I`m reluctant to fork out £160 for a part which MIGHT fix it. Boiler failed again the day after.
I would appreciate any suggestions before I call Engineer No3!!
Thanks very much

 

[Andygasman2010]

You do need a diverter valve i'm affraid. Apparently those gionnani diverter valves can be stripped and cleaned with a service kit. I've done that to the DHW side but not the diverter side. maybe worth looking into?... As for the ch not working sometimes, i supose if the diverter was sticking in hot water position it could give u this fault but it could also be a pcb/sensor issue. I'd sort the diverter out first then go from there

 

[kitch0978]

gat yourself htg and hw thermistor, numerous problems associated with these, bout 8 quid each, easy to change, do it whilst diverter is out, might as well

 

[alanry]

Thanks for the advice. It confirms that I was right to suspect the diverter valve. I forgot to mention that the HW thermistor was changed by the second enginerr, with no difference. Will change CH thermistor. Any suggestions as to where to get the parts?
Thanks again