Ravenheat RSF82E No Hot Water

[v8cavalier]

Hello

I'm about at the end of my patience with my boiler. The central heating side of it is working fine, however when I turn on the hot tap, it shuts off the flame and I get no hot water. I've tried turning the selector to DHW only, When I turn on the tap, the diverter valve plunger moves across and clicks the microswitch, but that's as far as it gets.
I've followed the troubleshooting guide in the manual, and this points to the microswitch being at fault... I've replaced this and it is still the same.

Can anyone shed any light on this? I've fairly recently replaced both thermistors, so I hope it's not them..

Thanks,
Mike

 

[picasso]

I would check the potentiometer for the hot water.

 

[v8cavalier]

Thanks picasso, I've popped my meter across the DHW potentiometer, and i'm getting a variable resistance when i move it so I assume all is ok there? I've metered the microswitch too and that is all ok as well..

 

[picasso]

check the wires for continuity from the microswitch to the board if ok I would think the pcb, (but I am not in front of your boiler so dont take my word for it)

 

[v8cavalier]

The wires from the microswitch are ok, I checked the switch at the plug on the board..

The board was my thoughts too, argh! I can't see it being much else with the central heating working ok and everything to the board working too...

Thanks

 

[v8cavalier]

Further to my above reply, would you think it would be the red ignition pcb? Or the actual main boiler board that's kippered?

Would the DHW pressure switch cause the fault too?

Thanks!

 

[picasso]

before you replace the board make sure you have continuity through the summer/winter switch.

View media item 35861

 

[Agile]

Further to my above reply, would you think it would be the red ignition pcb? Or the actual main boiler board that's kippered?

Thanks!

The ign pcb controls the ignition/combustion process.

Since the same process is followed regardless of the mode then the ign pcb is obviously working OK.

I suggest you measure the sensor resistance. Must be done with boiler completely cold.

Talking/writing does not find faults. Tests/measurements do!

It could well be the pcb but thats the last thing to consider.

Tony

 

[picasso]

main board if it is the board and DHW pressure switch ?

 

[Agile]

"DHW pressure switch"?

If you mean pump proving switch then I dont remember this boiler having one?

Tony

 

[v8cavalier]

I've put the meter across the summer/winter grey terminals on the main switch, and am getting nothing - there doesn't look to be an actual summer / winter switch as such.. the main switch has either DHW, off or DHW&CH,

It was the 2 grey terminals i've arrowed in yellow below

I tested it with the power on and the switch to DHW only

 

[picasso]

Would the DHW pressure switch cause the fault too?

I was questioning this sentence.

 

[v8cavalier]

The switch i've arrowed below

Is this a low water pressure switch? Would that reading incorrectly cause the boiler not to light?

 

[picasso]

you should have continuity across the grey terminals when on DHW or DHW/CH, the pressure switch would affect the ch if it was faulty.

 

[v8cavalier]

I have just metered the summer/winter switch again, I get continuity if I select DHW/CH, but not when turned just to DHW..

Thankyou for all the advice, it's much appreciated