Adivice on new CH & HW system in new house - Installed w

[deefadog]

Hi all, Need some outside advice. Living in a year old house (Barratts) it's a 3 storey house with a large HW storage tank. I know it may be impossible to answer my questions with out seeing it but I'll give it a go for now (I can take pics and give models numbers when i get home)

Lately we have been losing pressure (on the pressure gauge which should be at 1 bar) it's droping to nothing. (no sign of any leaks)

Now we have had the plumbers out through Barratts and they first change the pressure gauge) obviously made no difference, then after testing it my self I noticed that water was coming out of the blow off pipe outside the house every time the hot water came on. If i left the HW off, the Central Heating would be fine!

Now should the HW be linked to the pressure gauge, as i have had one of the plumbers say it should not effect it, it's only for the heating?

Thanks in advance

 

[deefadog]

Did not upload the pics last night, but can anyone take look at the this for me, just want to be sure that the pressure gauge should not rise when the HW comes on?

Thanks

 

[gas4you]

If, as it sounds, you have a system boiler, then the pressure gauge will rise when the HW or CH is on.

If, which I doubt, you have a combi, then no, you would not expect hardly any movement of the pressure gauge.

 

[deefadog]

Thanks for the reply!!

Yes it's a system boiler, the water comes out of the blow off pipe when the hot water is on, they have replaced the 90 degree releif valve (it's on the tank it self on the side), but it's still the same, is there anything else that could cause it?

Thanks

 

[gas4you]

As you now say it is the tprv on the unvented cylinder, then this is entirely different to a boiler fault.

The cyl stat needs to be checked that it is working and that the 2 port valve in the indirect flow to the HW cyl is working ok.

The expansion vessel charge on the cylinder also needs checking as does the incoming mains pressure.

I assume these numpties are registered for unvented HW cylinder installations

 

[deefadog]

Well i hope so, they are the contractors for the customer care team, but you know how they are!!! He told me that the gauge should not rise, but really did nothing but change the obvious parts.

It has 2 expansion tanks above the main tank if that maskes any differnce?

They did replace the tprv and the pressure gauge.

I'll try nad get the boss out, as he over saw the installtions apparentlly.