Hello all... Can anyone advise me on how to remove the large tapering red knob on the PRV? I spoke with a Baxi employee who told me that the red knob could be removed easily to reveal the seal and seating which may need a clean... I cannot fathom any way of removing it! It is quite loose until about 1/3 of a turn anticlockwise when it appears to engage the spring mechanism... We are loosing pressure over a few days. Any help would be greatly appreciated...

On Friday, 18 December 2015 16:02:57 UTC, Richardmerri wrote:
Hello all... Can anyone advise me on how to remove the large tapering red knob on the PRV? I spoke with a Baxi employee who told me that the red knob could be removed easily to reveal the seal and seating which may need a clean... I cannot fathom any way of removing it! It is quite loose until about 1/3 of a turn anticlockwise when it appears to engage the spring mechanism... We are loosing pressure over a few days. Any help would be greatly appreciated...

It could also be your pressure vessel diaphragm has ruptured if you are losing pressure in your system and having to keep topping up.

In which case the relief valve is doing it's job.

If you are losing pressure you need to start by ensuring the water loss is through the prv. Favourite method is to attach a poly bag over the end of the discharge pipe.
If the loss is elsewhere the bag will remain empty.
If the prv is letting water out there may be a loss of pressure cushion in the expansion vessel.
I've never been inclined to bugger about with trying to rectify a weepy prv as they are cheap items and readily available. You could remove the label on the top of the plastic knob to see if there is a screw etc.

On 18/12/2015 17:09, wrote:
If you are losing pressure you need to start by ensuring the water loss is through the prv. Favourite method is to attach a poly bag over the end of the discharge pipe.
If the loss is elsewhere the bag will remain empty.
If the prv is letting water out there may be a loss of pressure cushion in the expansion vessel.


I've never been inclined to bugger about with trying to rectify a weepy prv as they are cheap items and readily available. You could remove the label on the top of the plastic knob to see if there is a screw etc.

+1, once they are leaking I reckon they are dead. Note that they come in
just about all flavours of male/female inlet/outlet, but BES have always
had the one I need.

On Friday, 18 December 2015 16:02:57 UTC, Richardmerri wrote:
Hello all... Can anyone advise me on how to remove the large tapering red knob on the PRV? I spoke with a Baxi employee who told me that the red knob could be removed easily to reveal the seal and seating which may need a clean... I cannot fathom any way of removing it! It is quite loose until about 1/3 of a turn anticlockwise when it appears to engage the spring mechanism... We are loosing pressure over a few days. Any help would be greatly appreciated...

Thanks to all who have responded to my cry for help... PRV replacement fixed the problem... Thanks again all...

Richard.