new shower pump, new mixer valve, no hot water.

[benny80]

Hi
I've Recently had a new shower pump fitted in the airing cupboard. I've also had a new thermostatic mixer valve and shower head fitted. It's a gravity fed system. I now have no hot water from the shower. I think i can rule out the mixer valve being faulty because when this was fitted, it was tested and both hot and cold water could be felt, however the pressure was poor, hence the need for the pump.

Now, looking at how the pump has been fitted i think i can see the problem but would be very grateful for some expert insight as to whether i have got it sussed. Having run the shower for about 5 minutes there was no sign of the water getting hot, the water had been 'on' for around an hour so i felt all four pipes coming from the shower pump - all 4 were stone cold. I then referred to the shower pump manual and installation pages which clearly stated, and showed via the diagram, that the hot feed connection/supply to the shower pump should have been connected via a pipe that is connected to the vertical pipe from the hot water cylinder, below the t-junction of that pipe where the feeds branch off upstairs and downstairs (if that makes sense?).

The way it's fitted at the moment has the four pipes from the shower pump going straight up through the ceiling into the attic where connections are made to existing pipework and the existing hot/cold feeds to the mixer. This says to me that there is no hot water feed to the pump and hence no hot water to push to the mixer valve?

This is the shower pump: http://www.showerforce.com/ntpages/sfnturbo2

any help/comments greatly appreciated.

Thanks
Ben

 

[bobthebender]

Are the pipes all fitted correct on the pump..cold at one end & hot at the other ?
Is the cold feed coming from it's own tank connector ?
Has he teed the hot off of the vent pipe in roof ?
Does the instructions say it needs it's own feed from the cylinder or first draw off from the hot water feed pipe ?
so many questions

 

[benny80]

honest answer to those questions is god knows.
all i know is that the pump is working fine in that the pressure of the water has increased since it has been fitted. we have had a humming in one of the pipes since the pump was fitted when you turn a hot tap on anywhere in the house as well.

manufacturers instructions for hot supply to the pump states:

"Make your connection into the hot water supply pipe from the cylinder, ensuring that it is in the vertical pipe (below the expansion pipe tee). A minimum of 1 metre below the base of the cold water storage tank and the top of the hot water cylinder must be achieved. If this is not possible, a direct connection must be made from the hot water cylinder with an Essex Flange with dip tube."

from what i can see he has done neither of these things

 

[benny80]

have been up the loft to investigate this further.

from what i can see, the pipe that originally fed the hot water to the old mixer is located just underneath the tank in the attic and is teed off via a gate valve from the hot water pipe that comes from the top of the hot water cylinder in the AC. makes sense.

However, he has cut the pipe off at the gate valve and diverted that back down into the airing cupboard and into the hot inlet on the pump, he is then attempting to pump that water back up out of the pump, all the way back up into the attic underneath the tank and down to the new mixer valve in the wall - now that don't seem right to me! your talking roughly 8 metres of pipe!

the pipe that originally fed the cold in the old mixer valve is doing the same thing - although at this stage i wouldn't see a problem with that because there is no other way around it?

any clues?
cheers

 

[gas4you]

Sounds like the pump will suck in air from hot vent pipe to me rather than pull the hot water.

Should have hot water supplied by a surrey of essex flange on cylinder.

 

[benny80]

guy came back out last night. its working 'fine' now, but the sceptic in me is still not convinced it's working as effectively as it could do because there is roughly 6-8 meters of pipe that is not absolutely necessary - even he admitted that. Having said that he clearly did not want to move the pipes and t off at the cylinder as suggested here, and in the instructions unless absolutely necessary, so the hot feed to the pump is still coming from up in the attic at the point where the old mixer was fed from. he messed around with the new mixer valve to set the hot water temperature and it seems to be working now. just have to keep my eye on it i guess. i still cannot fathom why he just did not follow the instructions! he could have saved me roughly £30 on pipe and himself a few hours work.