Dufour Owners Association: new forum comment on Quick Hot Water Calorifier PRV

New comment from Paul White

Out of interest, what expansion vessel? We have the same problem as the original post on our D34. As far as I can see it's just the pressure relief valve doing it's job. The only solution I've come up with is, if I'm motoring for any time, to turn the domestic water pump off and leave a hot tap open (I usually open the one in the heads)


Original Post by Matthew Dellar

Quick Hot Water Calorifier PRV

<p>Hi </p>
<p>Can anyone help with advice on a Quick hot water calorifier? </p>
<p>I seem to be getting a small amount of water leaking from the pressure release valve on the Calorifier after running the engine. I have swapped the PRV for a new one but this didn't make any difference.</p>
<p>Has anyone had this problem or can advise on what could be wrong and how to fix?</p>
<p>Thanks, Matt.</p>

comment made on…

<p>Hi Matt Check your expansion vessel. It would have lost its expansion pressure .</p>
<p>it’s a classic case . There will be a data badge giving the correct expansion pressure.( normally 0.5-1.0 bar )</p>
<p>To carry this out shut off the inlet valve and pump. Open up a hot water out let . You will need a bicycle pump with a gauge . Take off the dust cap at the end of the the expansion vessel , and using the pump . Repressurise the vessel . You will note some more water run from the tap at the same time .as soon as this ends and you are at the correct pressure . Shut off the outlet tap .Remove bike pump.Turn on the inlet tap and pump . Now on heating the expansion will be taken up in the expansion tank .</p>
<p>if you loose pressure again in a short period you may need to replace the vessel . <br />Hope this helps . Steve </p>