Mixer shower tap problem.

[shabsburn]

Hello, I have had a shower mixer tap installed in place of my normal bath taps and the hot supply is very weak and when cold is turned on it goes back up to the cylinder pipe .

The system is a open vented system and the cold supply to the bath is from the mains.
Has anyone got a suggestion to the problem which is not too expensive?

 

[TicklyT]

Is your shower mixer suitable for use with a low pressure gravity system?
Your hot water pressure may be as low as 0.1 Bar, and many modern mixers are designed for 1.0 Bar minimum pressure.

Check valves in the feeds will stop backfeeding, but temperature adjustment is a problem with vastly differing pressures.

The most reliable way to equalise the cold pressure is to run a cold water feed from the cold storage tank.

A pressure reducing valve in the cold supply may do the job, but neither will work if the mixer is not suitable for the pressure available.

Pumping the hot feed is possible, but matching the cold feed pressure is problematic. Most would prefer to run a gravity cold feed, then pump both hot and cold to the mixer.

 

[Bahco]

The cold feed should be taken off the tank and not the mains if you have a cylinder.

 

[shabsburn]

ok...thanks for that...i have a nearly new normal central heating pump at home which was taken off by warm front recently...it it possible to connect that to the hot water system goint to the shower mixer to sort my problem out?

 

[Bahco]

The cold feed should be taken off the tank and not the mains if you have a cylinder.

Forget the pump.

 

[Homesafe]

What pump are you talking about?

 

[Nige F]

ok...thanks for that...i have a nearly new normal central heating pump at home which was taken off by warm front recently...it it possible to connect that to the hot water system goint to the shower mixer to sort my problem out?

possible but you`d be showering in rusty water . Has to be a dedicated shower pump

 

[shabsburn]

normal central heating pressure pump which was connected to the cold water downstairs but has been removed and a new 1 replaced upstairs nxt to the cold/hot water tank by warm front....

 

[Homesafe]

you want to connect a c.heating pump to the hot supply to the mixer is that what you mean .
I don't really know if you can do that, or how you would get it to work.
Maybe some of the guys on here will be able to give you more info.

If thats what I presume your thinking of .

 

[homes]

normal central heating pressure pump which was connected to the cold water downstairs but has been removed and a new 1 replaced upstairs nxt to the cold/hot water tank by warm front....

WHAT!!! you can't put a normal C.heating pump on DHW draw off, it will unbalance the pressure even more, you are a real spender aint ya? .