Urgent help reqd regarding gravity hot water

[bigdek]

The bloke next door to me is doing an attic conversion and has moved the cold water header tank that feeds the hot water cylinder and the cold taps in the bathroom.

It use to sit in the middle of the attic on a tressle approx 18 " high but now it is on the floor in the eaves Problem is the flow rate to the cold taps is now very poor but even worse there is no hot water coming from the taps.

The hot water cylinder is in a cupboard in the kitchen which is directly underneath the header tank but the hot water oulet comes back up into the attic and runs accross the attic floor and then back down to feed the bathroom and kitchen .

He can possibly raise the tank by 6" but no more. will this be enough to get a flow ?

Can a pump be fiited in line at the hot water cylinder to pump the hot water due to the negative head ??

Any help appreciated ?

 

[oilman]

It sounds like you have an airlock in the hot pipe. I bet it hasn't got a bleed vent in it. Once the air is out of it, things should be ok until it runs out of water and you have to bleed it again.

 

[bigdek]

whats the best way to bleed this

 

[ChrisR]

As oilman said - it SHOULD have a proper bleed point fitted in the pipe. If there's a compression joint in the line you can undo it to let trapped air out, but it wil leak water out too.
If you want water to go uphill, ie to a point above the level of the (bottom of the )cistern, or almost level with it, you'll need a negative head pump.

I hope the "bloke next door" hasn't moved YOUR cistern!

 

[bigdek]

would raising the tank 6 " work ??

 

[ChrisR]

Doubt it. The actual head you have is from the water level in the cistern to where the pipe is, which is probably a foot or so?? 18 inches wouldn't make a lot of difference I'd have thought
You could try sucking at the end of the pipe - preferably with a "wet" vacuum cleaner but you can get away with a dry one if you suck through a bit of cloth and remove hose quick when the water comes

There's always the standard method - connect a mains hose to the outlet which isn't working, and push the air back up the pipe.

 

[bigdek]

think a pump will be needed as the bottom of the tank and the hot pipe that feeds the bathromm are almost level ..

Can you recommend a pump and where to buy from ??

 

[DP]

Must be a very good neighbour to go to all that trouble.

 

[bigdek]

What model of pump can be used ?

 

[stephen_smit]

monsoon negative head pump. about £450