Heating engineers help please

Thanks for that, they aren't too far away at all. I'll have a google.

 

I'll have a look to see how it opens. So far I undid one screw and that gave access to a 3 pin plug for the electricals. I could see part of a pcb and it was soaked.

Edit: The case just clips together. Inside looks better than I hoped.

 

Is that water, or is it shiney coating on the PCB?

 

It’s shiny surface.
Rather than pay £200 for just a new actuator, could I replace the whole 3 way ball valve and actuator with a different make that’s cheaper?

 

That may not be possible. The boiler pcb/relays with be designed to operate with a particular valve. For instance on a Worcester heatslave which is a comparable oil combi to yours (both Marmite) the pcb outputs a live to the motorised valve when there is a demand for heat from the central heating control stat. Once this demand is satisfied then power to the valve is de-energised and a spring returns the actuator to the resting hot water position. On your model I’m fairly sure that the pcb uses power to open the valve and then uses power on a different output to motor the valve back to the resting position. So you can see you could run into all sorts of issues if you tried to fit a different valve. It’s possible that it may never close once it opens the first time. So you’d either never be able to get either heating or hot water.

 

Thanks mate. From the research I’ve done that’s exactly how it operates.
Still waiting to hear from the engineer who fitted it, he was unwell with the squirts after an emergency call out.
The boiler this replaced was a Heatslave, in when we bought the house. It lasted 6-7 years.

 

That happens sometimes especially if you get a fright when the customer opens the door

 

Thanks for everything so far.
One last question please.

I’ve ordered a replacement actuator from Heating World of Spares and I’d like to replace the pressure reducing valve as well in case it caused the washer to leak in the first place.

They list https://www.hwos.co.uk/tradestore/product/pressure-reducing-valve-15mm-rv-15
but say it only controls dynamic pressure. Is this adequate or could downstream pressure rise when the boiler isn’t in use?

They also list https://www.hwos.co.uk/tradestore/product/mini-pressure-reducing-valve-with-gauge-miniprv
which is £10 cheaper and comes with a gauge but doesn’t mention dynamic or static control, just that it’s mini but looks pretty much the same size on the photo.

Which do you think would be better, if either?

 

I’m not an expert on these but I think the dynamic valves are better at controlling the water pressure as it flows, leading to less fluctuations. A static valve is just that, static, so doesn’t adjust the pressure as well when there is greater flow in the pipe.

do you already have a pressure limiting valve fitted in your system? Was it added by the installer due to you having a mains water inlet pressure that exceeds the recommendation of the boiler manufacturers?

 

Yes there’s one fitted but it looks cruddy inside and I’m not convinced it’s working.
The max inlet pressure for the boiler is 3 bar, mine appears to be 6 bar.

 

Or a bag of rice........if any left in the shop

 

Thanks but tried it again today and it doesn’t move to switch between hot water and heating.