PRV Replacement

[rad_pete]

Ok, so what's the score then? Drain the system (which I need to do anyway) and then test the pressure in the expansion vessel?

Given that there was no water coming out the valve though, does that still mean that the vessel is ok?

 

[CBF]

Ok, so what's the score then? Drain the system (which I need to do anyway) and then test the pressure in the expansion vessel?

Given that there was no water coming out the valve though, does that still mean that the vessel is ok?

to test the EV pressure you can't have any pressure in the boiler or heating system (if you aren't isolating the boiler), as you are changing the prv anyway open the prv up & leave it open (you should be able to get to a point just before it slams shut where it will stay open on it's own just takes a few tries), then test the EV pressure if it needs topping up when you pump it up you will prob find water coming out the prv pipe the pressure is normally between 0.75- 1.0 bar but check the MI or the EV data badge (if it has one), water coming out the EV test/pressure valve will indicate either it is knackered or that it is completely empty, if you didn't get water out this doesn't mean it doesn't need repressurising.

 

[rad_pete]

Excellent, that is for that.

I've just drained the system so ill check out the ev before swapping the PRV out for the new one then.

My plan is to the check ev, pump up if need be ( I guess it's a good sign that water wasn't coming out of the valve) and then I'll swap out the PRV and then fill the system and add the inhibitor.

From what you've mention, I'll then see how it goes before thinking about the leak sealer.

I take if that when full the system, it's going to be normal to have pressure variations while I'm bleeding the radiators?

Thanks

 

[CBF]

yes the pressure will drop as you get the air out, but remember you need an open end either the prv or the drain off on the heating to test the EV pressure don't just drain it then turn everything back off & test the EV you will get a false reading & if you can't get the required pressure in the EV after pumping it up then it's knackered, if that happens the cheapest way is to fix an external one on the return pipe as close to the boiler as possible.

 

[rad_pete]

awesome.

i'm sure i'll be back in touch if/when i run in to trouble

thanks again, great forum!