Feed and Vent fun :DDDDD

[Vee]

See edit above.

 

[Vee]

yea but would it open under gravity and not stick

Have got two systems like this operational now in their sixth year and no problems.

 

[ShaunCorbs]

Have got two systems like this operational now in their sixth year and no problems.

head of the tanks vs the position of check?

 

[Vee]

Top of system for header. Followed by gate or lever in downfeed, so you can turn system of and for easy replacement of check valve. I positioned them in airing cupboard. Check valve can be anywhere between isolation valve and where it tees into the system.

 

[ShaunCorbs]

Top of system for header. Followed by gate or lever in downfeed, so you can turn system of and for easy replacement of check valve. I positioned them in airing cupboard. Check valve can be anywhere between isolation valve and where it tees into the system.

Trying to work out how much head you have

 

[Vee]

Trying to work out how much head you have

Not sure how to read that?

 

[fixitflav]

Use the header as top up, with gate and non return fitted.

Does the gate valve stay open in normal operation?

I can't see how this differs from just having an expansion vessel, but with pre-charge pressure somewhat lower than normal.
Still need to put the expansion vessel connection in the right place, to avoid having negative pressure somewhere.

 

[fixitflav]

I am actually having the same problem trying to decide how I convert a gravity hot water/pumped rads to all pumped on a very old system, without pump over or corrosion.

I converted mine about 20 years back. Old cast iron floorstanding boiler, gravity HW, pump next to boiler, pumping downwards. No controls. Cold feed to boiler return.
Scrapped the boiler and installed wall-mounted condensing. Moved the pump to the airing cupboard, added diverter valve (system W), open vent, cold feed and DV in the airing cupboard. Added cylinder and room stats. Re-used the gravity 28mm pipes as pump suction and cylinder return.
Still working OK.

 

[Vee]

Does the gate valve stay open in normal operation?

I can't see how this differs from just having an expansion vessel, but with pre-charge pressure somewhat lower than normal.
Still need to put the expansion vessel connection in the right place, to avoid having negative pressure somewhere.

Gate valve stays open. Ans yes you can just seal, add vessel and PRV and have virtually no pressure. Its just convenient using the existing header instead of a filling loop if its already there.

 

[fixitflav]

Gate valve stays open. Ans yes you can just seal, add vessel and PRV and have virtually no pressure. Its just convenient using the existing header instead of a filling loop if its already there.

OK thanks