Grant Combi V3 90 boiler - pressure switch leak

[Dene71]

Hello

I have a leak in the pressure switch of my Combi V3 90 boiler, but am having difficulty finding anywhere online showing how to fix or replace it.

Would anyone be able to help with this, or know of anywhere online to find instructions?

Thanks in advance,
Dene.

 

[easyflow]

If its the low pressure sensor you are talking about, this is plastic with brass male fitting that just unscrews.
You will need to isolate boiler via the service valves and drain the boiler, Release eletrical connection unscrew sensor renew sensor or if you are lucky just the rubber seal, screw sensor back into housing job done.

 

[Dene71]

Thanks for this.

The sensor in question has a pin through the fitting (it is possibly an older model), not a screw in. Is there any way to seal this type of fitting - or would a newer pressure switch be the only way to go?

Thanks again.

 

[oilhead]

Is your 'pressure switch' the diaphragm operated diverter valve? If so and it is leaking from the pin below the microswitch, then you can isolate the cold water inlet, remove the microswitch by withdrawing the horseshoe washer, which will enable you to remove the top of the diaphragm valve (8 screws) and then you can replace the O ring and with some silicon grease, reinstate the seal. If you get a diaphragm service kit, you will get all the bits you need. Alternatively, you can try to force some silicon grease down the side of the pin before going to all the above trouble.

 

[Dene71]

Is your 'pressure switch' the diaphragm operated diverter valve?

Hey, thanks for this but no, it's not the diverter valve. Definitely the pressure switch - the diverter valve is on the other side.

Pressure switch has 4 screws and a fitting at the back for fitting on to the pipe with a pin down through it. The boiler is approx. 6 years old.

Just looking for a way to replace this.

 

[cozzmic]

The brass nut with the hole in it for the pin unscrews from the bit welded onto the pipe and the new pressure switch screws into it.