Central Heating & Hot Water Issues - Help with Boiler Please!

Talldave

It needs to be V4073A1039. If an ebay seller hasn't stated the full code, message them and confirm. That's often the way to grab a bargain.

The other approach is to get the valve base and top motor assembly separately if you see cheap ones going individually.

Once you've got your bargain valve, contact a plumber to ask for a labour quote as you have the valve already.

JC9

Thanks so much for the help everyone, really appreciated.

I'm also going on the assumption that the wiring is ok, otherwise I'd have thought the previous owners would've fixed this in the previous 15 years they were at the house since the heating system is the original one. My only slight concern in regards to wiring is the boiler cycling on/off, but if it's constantly supplying HW & CH, then maybe the tank is hitting the max temperature and telling the boiler to stop? The thermostat doesn't seem like it's regulating CH temp, even if it's set to 10 degrees in the hall, the radiators will still get hot to the touch.

I'll go for the recommended fix and buy a genuine Honeywell valve then get a few quotes for labour. Will the system need to be drained down or is it possible to isolate the pipework for replacing the valve?

And one final question, this one is truly baffling me; why is there pipework which completely bypasses the 3 port valve? Does anyone else have this? I've included a better photo of it and highlighted the pipework between the pump & 3 port valve with a red line.

Thanks again guys, this forum is incredibly helpful and full of knowledge!

thorganby

JC9 wrote: »

Thanks so much for the help everyone, really appreciated.

I'm also going on the assumption that the wiring is ok, otherwise I'd have thought the previous owners would've fixed this in the previous 15 years they were at the house since the heating system is the original one. My only slight concern in regards to wiring is the boiler cycling on/off, but if it's constantly supplying HW & CH, then maybe the tank is hitting the max temperature and telling the boiler to stop? The thermostat doesn't seem like it's regulating CH temp, even if it's set to 10 degrees in the hall, the radiators will still get hot to the touch.

I'll go for the recommended fix and buy a genuine Honeywell valve then get a few quotes for labour. Will the system need to be drained down or is it possible to isolate the pipework for replacing the valve?

And one final question, this one is truly baffling me; why is there pipework which completely bypasses the 3 port valve? Does anyone else have this? I've included a better photo of it and highlighted the pipework between the pump & 3 port valve with a red line.

Thanks again guys, this forum is incredibly helpful and full of knowledge!

To replace the original Honeywell 3 port valves, the system had to be drained down but you may not need a complete new valve.

The current Honeywell valves have a small raised dimple on the cover at the fixing screw end which indicates that the valve head is removable:



The motorised valve head can easily be removed on these later valves by simply removing two screws.

If you remove the cover retaining screw, you will see the two diagonally opposite screws that secure the motorised head to the brass valve:



With the head removed it's operation can be checked and the valve spindle can be rotated to check if the valve operates freely or is seized.

If the valve has seized it should be possible to turn it back and forth with pliers to free it up, as the motor will only operate it if it rotates freely:



The gate valves are not standard and allow the flow of both heating and hot water circuits to be bypassed. I would expect these to normally be fully open.

Talldave

The symptoms indicate that the valve is siezed because the spring return isn't happening.

thorganby

Talldave wrote: »

The symptoms indicate that the valve is siezed because the spring return isn't happening.

Agreed but this is MSE.

Five minutes with a screwdriver would prove this and another five minutes with pliers and some penetrating oil would likely free the spindle without paying for either a new part or a plumber to fit it!

:beer: