Cylinder immersion heater prv passing

[proelitegas]

Hi I have had a call from a customer who claims his relief valve is discharging. He has a unvented cylinder with immersion heaters. Now from what I know he has a combined prv with a 90 degree temp probe and prv is set at 7 bar. Now it could be the valve is passing or the cylinder is over heating and the valve is doing its job. Question is how can I test the stat on the immersion heater is working and not allowing the temp to go above 65degrees?

 

[Whn1]

Set it and check the water temp.

 

[Whn1]

Also check the temp of the water from the tundish to see if it's temp related.

 

[Whyme]

Is it a combined temp and pressure relief ( sometimes 4 bar) cos the 7 bar is usually on the mains feed. If it aint got an expansion vessal the air bubble could have gone from the cylinder. He should have noticed if it was hot enough to make the temp side blow off.

 

[proelitegas]

I've believe there is a expansion vessel there. It's a ladies gym good point totally forgot about the expansion vessel loosing charge and blowing off.. Been a long day lol

 

[AWheating]

check expansion vessel, pressure reducing valve/water pressures etc.....

the immersion should have a non resetting cut out, this if working should trip if the immersion stat has failed so you would not get any hot water.

 

[proelitegas]

Update cylinder had 2 stats one at bottom and one at top. Tested resistance on top stat it was 19.5 ohms bottom one was ol but had a reset on it which I pressed and it then also reg 19.5 ohms. Expansion vessel was flat so recharged to 3 bar and left hoping all is good. Now cylinder has the bs kite mark and and immersion heaters are standard but have the reset on the stat.

 

[Whyme]

If expansion was flat thats your problem solved..

 

[chris watkins]

Have we got any Part G tickets knocking around here ?????
Not being funny but this is fairly basic stuff & I am getting worried if people are having to be reminded to check an expansion vessel because a prv is discharging !

(If you install or work on these systems you are required by Law to have your Part G ticket)

 

[proelitegas]

Got my unvented ticket mate this post was so that I could get some opinions, tbh I haven't worked on a cylinder for a while but fair comment a flat vessel symptoms are passing prv..

 

[tamz]

you are required by Law to have your Part G ticket)

No G's up here Chris but i live in the land of the free :smile: (not that stds are any better up here)

 

[Dotty]

No G's up here Chris but i live in the land of the free :smile: (not that stds are any better up here)

The land of the poor and the dispossessed if the SNP has its way.....