No hot water to downstairs shower room

[Mason84]

Hello all.

I'm a newby to this I'm desperate for some plumbing advise

I have recently moved into a house. (3months) ago. And have been having serious issues with a downstairs en suite shower room.
From day one in this house the thermostatic mixer shower has not worked. It was either scolding hot or freezing cold, no mix whatsoever so i removed it tested the cartridge and found it to be faulty. Unable to get a replacement cartridge i was forced to isolate it and remove the whole valve. which involved butchering the tiles in the shower (Last month)

Today I bit the bullet and bought a nice new triton dart mixer valve and installed it. Turned the water back on to the en suite and now I can't get any hot water to it. I turn the shower on and it runs but as soon as i turn the thermostat to hot it stops. Checked the sink taps and The cold is fine but the hot will literally trickle out (cold) then stop.

The hot feed to en suite tees out of the hot water cylinder feed situated in the airing cupboard, goes up into loft (from here onwards its cold to touch) across and then down through upstairs to the downstairs shower room. The cold follows same route but comes from the water tank in loft.

Any advise, questions or comments will be greatly appreciated

 

[picasso]

It sounds like the hot is airlocked, are there any vents on the highest points of the pipe work ?

 

[Mason84]

I found two in the airing cupboard, one of them I undone and it released a bit of air then water came through. But the other one I released and took the cap complletely off but nothing comes through?
Any ideas. This pipe work is all red hot by the way. But the feed going up to the loft for the shower starts hot at the cylinder but then gets cooler the higher you get...
Any ideas?

I'm off to work but back tonight cheers

 

[Mason84]

I have just rigged up the washing machine hose between the hot and cold valves under the sink and opened them up.
It pushed through the system, up to the header tank and out the overflow..
but the hot water is still not coming through.

Does anyone know the best/easiest way to push the air out of the hot water pipe?

 

[duffin]

right. does cold water come from the shower when set to warm? if so, take off shower head and put your thumb over it. then turn on the shower until water goes into the expansion tank. sounds like the en-suite itself is airlocked, not the rest of the system. if the shower trick doesn't work, and you have a mixer tap on the basin then finger over end and turn on both. that should clear it. or if separate taps then a wet hoover on the hot tap or a piece of pipe to link them, then hot on and cold. should clear it

 

[Mason84]

Ok I have a mixer tap in there so I have done what youve said and turned the cold tap on opened the hot tap and held my thumb over it.
This forced the cold up the hot pipe. Held it for few mins then released.
I turned off the cold and let the hot run out what was backed up but it just spat a bit and eventually stopped?