anti gravity loop VS. automatic bleed valve (OR both)

[Monkey3]

Hi,

I'm in the process of upgrading our bathroom and en suite by (among many other things) adding a pump.

The pump has to go in the loft (no room as base of HWST) but is a good 600mm below the bottom of the CWST.
I've fitted a Surrey flange (again, no room to fit an Essex flange as I can't remove the cylinder) and an anti gravity loop.

Is it the case that you need either an anti-gravity loop or an automatic bleed valve or should I use both?

Also, would this question be irrelevant if I used a one way valve on the hot feed (after the pump)?


So, it would go:

HWST
Surrey flange
anti-gravity loop
automatic bleed valve
pump
one-way valve​

Is this overkill?

Thanks for any advice you can give me,

Russell.

 

[stevetheplumber]

ive had a lot of grief with pumps over the years do it exactly as they say in the mi's because any deviation will void any warranty remember to check the water temperature at the top of the tank is below the maximum alowed this generally means the thermostat one third of the way up needs to be 7 degrees below max at least failing to meet this criteria probable cost me over £1000 pounds

 

[Phil]

Don't forget the non return valve must be a low pressure flap type, don't try fitting a mains pressure one!

What make of pump is this?

 

[Phil]

ive had a lot of grief with pumps over the years do it exactly as they say in the mi's because any deviation will void any warranty remember to check the water temperature at the top of the tank is below the maximum alowed this generally means the thermostat one third of the way up needs to be 7 degrees below max at least failing to meet this criteria probable cost me over £1000 pounds

Sounds interesting Steve, what happend there?

 

[Monkey3]

ok, stat one 3rd way up the HWST, check.
and a low pressure flap type valve, check.

The pump is a Stuart Turner 3 bar universal.

I've just read a lot about using an anti gravity loop and a lot about the automatic bleed valve but nothing about using both.

 

[Phil]

I would just have the anti gravity loop if there is room in the airing cupboard, this stops air from the cylinder getting into the pump supply if you have the pump in the loft.

You just need it to dip down by 300mm or whatever it is from your surrey flange and then back up and into the pump. If you can I would machine bend (or spring) the 22mm inlet pipework, don't have too many tight bends.

 

[markfxy]

If you don't fit the anti gravity loop the warranty will be void

 

[Monkey3]

the anti gravity loop's installed all good but do I also need the auto bleed valve and the one way valve as well?

 

[markfxy]

no its not necessary

 

[Monkey3]

but would it be beneficial?
is it worth adding the one way?

 

[markfxy]

what's the point of a check valve? once you shut the shower valve you can't draw any water back out of it! an automatic air vent could cause problems in the future you could use a manual one for the initial commissioning although I wouldn't bother

 

[Monkey3]

Ok, I did think that but the documentation says (in bold) "do not install a non-return valve in the inlet to the pump".
By that I read you need one but just not before the pump.

in that case I'll go anti-g loop, pump, shower...

thanks mark

 

[Gray0689]

Non return should be used after pump( and don't use a flap non return valve)
These are for gravity not pumped

 

[Phil]

I've never tried fitting a mains pressure non return valve on shower pump pipework, my guess is the pump would not turn on in the first place though Gray?

 

[BLOD]

quite a common problem with shower pumps is the pump "pulsing" on and off when you close the shower valve, a check valve on the hot after the pump usually sorts this.

 

[Gray0689]

I've never tried fitting a mains pressure non return valve on shower pump pipework, my guess is the pump would not turn on in the first place though Gray?

Try it and see then

 

[Gray0689]

quite a common problem with shower pumps is the pump "pulsing" on and off when you close the shower valve, a check valve on the hot after the pump usually sorts this.

Totally agree