No hot water through shower

[Kwhizz]

Hi, I have just had a thermo shower installed with a new 2.0 bar Grundfos pump. The water pressure is good but there is no hot water coming through at all. The pipe feeding the pump isnt warm but the tank is full of hot water. The rest of the house is being fed with hot water............can anyone help please???

 

[Gray0689]

You sure it's plumbed right??

 

[Plumbstar Tom]

possibly an air lock

does the pump kick in?

Can you pipe it up with out the pump to flush

have you checked the filters on the pump?

have you checked the filters on the shower?

 

[Kwhizz]

Yes the pump kicks in and the pressure if fine. The pump and the filters are brand new this week, when the pump is off (isolated) no hot water comes to the shower either.
As for an air lock, the fitter said he ran both hot and cold through the pump into buckets and everything was fine but he had no hot water due to the cylinder being empty.

 

[Gray0689]

Then why did he not heat the water to test???

 

[Kwhizz]

I cant answer that, he was doing me a favour coming in for the morning so close to Xmas. He is asking around also if anyone he knows what the problem may be.

 

[Phil]

Dangle the shower hose in the tray with the head off and put it on full hot this should get the air out, make sure he hasn't left the isolating valve off at the pump, if fitted?

 

[Kwhizz]

Thank you for trying to help, I do appreciate yr feedback,
My shower head is fixed and flows from the ceiling. I have checked both isolators and they are open.
I think my only avenue of investigation is to check that the isolator is definitely opening although they are both new this week also

 

[Phil]

What has he used for his hot take off from the cylinder? Essex/Surrey flange? or simply tee'd off the underside off the horizontal draw off?

Any one is okay.

 

[Kwhizz]

It is an Essex Flange going by the google images I looked up...............the draw off of the cylinder is the first / Highest draw but only by 2 inches or so.

 

[gaspastemania]

is it a mixer?

 

[garrywhite]

Sounds like not enough flow from shower to activate flow switch on pump. Especially if shower head from ceiling. You probably need a negative head pump.

 

[Kwhizz]

Thank you all once again for your input, the plumber has been in contact with Grundfos to check that all his connections are correct and that he has the positioning in the correct place also. I have the correct pump and it appears to be correctly fitted, just no hot water.
My shower is a mixer thermostatic shower.
Will I cause any damage if I turn the cold feed off and just allow the hot to flow through the pump? At least then I will know if the hot water pipe is bloked in some way!!

 

[gaspastemania]

Firstly you defo have right shower for system???
Secondly i come across this alot is the cold feed on a main? if so needs prv then hey presto working shower!!
Common schoolboy error

 

[Gray0689]

Firstly you defo have right shower for system???
Secondly i come across this alot is the cold feed on a main? if so needs prv then hey presto working shower!!
Common schoolboy error

Check to make sure cold feed from tank not mains as GPA has stated
But if it is it needs changing as cant pump from mains

 

[gaspastemania]

I quite often get calls from so called bathroom companies abl=out stuff like this . Makes one wonder at times .

 

[Kwhizz]

No the pump is defo not fed from the mains supply, the pipes had to be adjusted slightly in the loft so they fell below my water tank as recommended by Grundfos help line.

 

[PlumbBobBob]

you said both isolators were open is this a single sided pump or double. there are four isolators on a double pump on both inlet and outlet

 

[Kwhizz]

my pump is a 2.0 bar grundfos pump, it has an inlet for each of the cold and hot and an out let for each of the hot and cold.
I think I have cleared some air in the system.................the hot water has now reached the pump but is very slowly creaping up the pipe. I have to keep turning the pump isolator swith on and off.
I hope this is a the solution, thank you all, merry xmas

 

[Phil]

So the pipework goes up into the loft, along the floor and down to the shower valve. I'd be trying to bleed air out of the air vents located highest point of the outlet pipework.

 

[Kwhizz]

hmmm interesting, what do the air vents look like, I have the plastic piping and not copper piping, does this make a difference?

 

[Phil]

Dont know about plastic but if copper they would be coming out of a tee into say 6 inches of pipe and have two caps on the end with knurled or hex screws in the top.

Air collects at the highest point in the pipework, without these how does he expect to bleed the air out?

 

[Kwhizz]

I have checked in the loft, there are no air vents. I guess the only thing left to do is detach the hot water pipe from back of shower and bleed that way, not ideal as I have to cut into my wall to do so.
I appreciate your help this close to xmas

 

[Phil]

Its a shame its a fixed ceiling mounted showerhead, it makes it harder to bleed, although if you have a wetvac you can unscrew the showerhead and put the vac on the pipe on full hot, this will pull the airlock out.

Thats what I'd do first to get it going.

 

[Kwhizz]

I dont have a wet vac, I should be able to unscrew the head, will that help at all?