Ravenheat LS80 CH always on

[Sgt.Colon]

Hello all,

I was hoping someone will be able to help me please?

I have a Ravenheat LS80 boiler and the Diverter was leaking. I bought a new diverter and replaced it along with the two thermistors. Once this was done I turned the boiler back on and the central heating came on and the only way to get it to go off was to either unplug the thermistor by the pump or to turn off the boiler.

I thought it maybe a diverter problem, so I put the old diverter back on and the boiler still fired up running the CH. So I put the new diverter back on.

I have turned the CH and DHW knobs right down and the CH doesn't go off. I have also set it to summer only and the CH doesn't go off. I have also removed the wires from the room thermostat and the CH doesn't go off.

Any help much appreciated.

Thanks in advance.

 

[picasso]

Check the value of the thermistor you have fitted , the main t/mister brings on the frost stat when it thinks the water in the boiler is @ 5c

 

[oilhead]

Swap the two thermistors over before you do much else. If the fault persists then there is a problem with that circuit, maybe PCB.

 

[dilalio]

Or perhaps know what is in the realm of your DIY and what is not.

 

[Sgt.Colon]

I'll check the thermistors later and report back.

My realm is not too bad. I'm not heating engineer though but I do know this boiler pretty well.

 

[oilhead]

I'll check the thermistors later and report back.

My realm is not too bad. I'm not heating engineer though but I do know this boiler pretty well.

So does anyone who has had one!!!!!

 

[Sgt.Colon]

Too true Oilhead.

Okay I've tested the thermistors on my multimeter and one was coming back at 12000 and one was coming back at 14000. I've swapped the 14000 one out for one that was reading just under 12000 and still the heating is coming straight on as soon as I turn the boiler on. Is it looking like a faulty PCB do people think?

Thanks.

 

[Sgt.Colon]

Bump. Thanks.

 

[dilalio]

Frost stat?

 

[Sgt.Colon]

Do you know where I might find that on the boiler please?

On looking at the manual for the LS80 I don't think it has a frost stat?

 

[oilhead]

There is no frost stat built into the boiler. Do you have a room stat? If so, what make and model. What programmer do you have?

 

[picasso]

The instructions that I looked at say it has frost protection built in , really need the gc number.

 

[Sgt.Colon]

Oilhead, I do have a room thermostat. It's a honeywell one. Not sure on the model number as it's just a dial on the wall down stairs. When you say programmer do you mean the clock and PCB on the boiler? If so it's the one that came with the boiler, which I think was fitted in about 2003.

Picasso, Please could you tell me where I can find the GC number?

Thanks guys.