Plumbing Question - Shower not hot

[Avo Mk8]

This?
View attachment 107974

Thanks
I don't want to hijack Mr moooore's contribution, but that seems to be a pump for hot and cold, maybe for the shower?
Is that a dented flexi or just my eyes?
Does it come on when you run the shower - should be able to tell from the noise/vibration!

 

[LukeD]

Its a temp controller for underfloor heating systems. But can still be used

Thanks again for talking me through - Again I do feel this might have happened since the new boiler but I could be way off.

Is this what you want?

View attachment 107969

and do you know what this is> it's in a cupboard near the shower room?

View attachment 107970

If you want higher def pictures let me know.

temp control unit designed for underfloor systems .But its fine

 

[Mark Wright]

Seems to.

 

[Mark Wright]

ill have a feel of those flexi pipes and see if they get hot?

I think that pump was fitted/replaced when the boiler was. So if the pump comes on with the shower and not the tap - the shower is fed from a different source?

 

[brianmoooore]

The feed for the shower hot does come from a special fitting that draws the water from slightly down the cylinder, and that is most definitely a shower pump on the end of the pipe that feeds from it.
Follow the flex from the pump to where it connects to a FCU, and see if it is switched on.
Also, check that the gate valve with the red wheel handle, near the top of the cylinder is fully turned on.

 

[Mark Wright]

The feed for the shower hot does come from a special fitting that draws the water from slightly down the cylinder, and that is most definitely a shower pump on the end of the pipe that feeds from it.
Follow the flex from the pump to where it connects to a FCU, and see if it is switched on.
Also, check that the gate valve with the red wheel handle, near the top of the cylinder is fully turned on.

Hi yes the pump comes on with the shower. I posted a video above but it's probably not showing

With the shower running the two flexi pipes at the front of the pump are warm but not hot

 

[Mark Wright]

The gate valve is open full - I closed it to see what would happen and it was still slightly warm? maybe cos the pipes were warm.

So I'm guessing something is not right with the feed to the pump. But cant understand why the tap is hot because it's from the same tank.

 

[brianmoooore]

Where does the flex from the pump go?

 

[Mark Wright]

The cable does go to an FCU and appears to be on.

 

[Mark Wright]

The cable to the immersion heater at the top is switched off?????

Ill leave it on an hour?

 

[Mark Wright]

I've rewired the cable to the immersion heater and ill do a continuity test on the element.

 

[brianmoooore]

The immersion heater would normally be switched off. It's only there to a) block up the big hole in the cylinder, and b) as an emergency backup if the boiler is out of order.
The problem with the shower is definitely the non working of the shower pump. Everything that has been discussed before is now irrelevant.
Do you have a non contact voltage detector (Volt Stick)? If so, wave it around the pump cable to see if it is live.

 

[mainline]

The immersion heater would normally be switched off. It's only there to a) block up the big hole in the cylinder, and b) as an emergency backup if the boiler is out of order.
The problem with the shower is definitely the non working of the shower pump. Everything that has been discussed before is now irrelevant.
Do you have a non contact voltage detector (Volt Stick)? If so, wave it around the pump cable to see if it is live.

The OP said that the pump comes on with the shower #66

 

[brianmoooore]

Ah, so that's what that short video was about. Doesn't come over very well on a laptop without sound. Listened to it on my phone now, and it doesn't sound very happy, but having been asked many times to diagnose car faults from videos, I know that's the norm.
The black connectors at the top of the pump flexible pipes often have quarter turn isolator valves built into them. If they are present, are they all fully on?
I've also come across pumps where there are little mesh filters built into the rubber washers between the nuts at the bottom of the flexible pipes and the pump.
All comments about the shower valve having a to high minimum pressure requirement are now invalid. Something's blocking the hot water flow.

 

[brianmoooore]

The connection at the top of the cylinder is known as a Sussex flange. Google it to see how it works.