Baxi Bermuda no hot water

[SSE]

As usual, a problem arises nearly last thing on a Friday!! Was wiring a kitchen for someone this week & the customer noticed this afternoon before I finished there was no hot water. Central heating is working fine. The back of the programmer shows it as fully pumped on the selector. Getting no power at the cylinder stat, thought it was maybe the programmer so linked it out & still nothing. Had a quick look under the floor, can’t see where the cable goes but have found the pump. Should there be a mid valve somewhere? Can’t see one anywhere near at all. No sign of a JB under floor either. All I can see is cable that goes to pump from the programmer & cable that goes to baxi from boiler.

 

[SSE]

As usual, a problem arises nearly last thing on a Friday!! Was wiring a kitchen for someone this week & the customer noticed this afternoon before I finished there was no hot water. Central heating is working fine. The back of the programmer shows it as fully pumped on the selector. Getting no power at the cylinder stat, thought it was maybe the programmer so linked it out & still nothing. Had a quick look under the floor, can’t see where the cable goes but have found the pump. Should there be a mid valve somewhere? Can’t see one anywhere near at all. No sign of a JB under floor either. All I can see is cable that goes to pump from the programmer & cable that goes to baxi from boiler.

 

[UNG]

Have you located the wiring centre that is normally located by the hot water tank,
It sounds like a motorised valve has failed and this is normally close to the wiring centre you should be able to manually operate the valve which will fire the boiler an start the pump

 

[SSE]

Have you located the wiring centre that is normally located by the hot water tank,
It sounds like a motorised valve has failed and this is normally close to the wiring centre you should be able to manually operate the valve which will fire the boiler an start the pump

Can’t find the wiring centre, thought it would be under the floor beside the Baxi boiler as that’s where the pump is. Would it now be wired into the cylinder stat before the valve first though? I’m getting no power at the cylinder stat at all.

 

[UNG]

I'm assuming you have not altered any of the heating wiring while wiring the kitchen
Looking at the programmer wiring something doesn't look right when you compare it to a Y plan diagram, I'm not certain this heating system has worked properly since install, if you try to run only the hot water does that work
As I said previously you really need to locate the wiring centre and motorised valve and then check the wiring and valve operation
If you are not familiar with heating systems some useful info can be found here Y Plan central heating system - https://www.flameport.com/electric/central_heating/heating_wiring_Y_plan.cs4

 

[brianmoooore]

HW 'on ' should normally connect straight to the cylinder stat. Stat should then go to motor of valve.
At first sight, it look kike a break in the prog. to stat wire somewhere.

 

[SSE]

I'm assuming you have not altered any of the heating wiring while wiring the kitchen

Looking at the programmer wiring something doesn't look right when you compare it to a Y plan diagram, I'm not certain this heating system has worked properly since install, if you try to run only the hot water does that work
As I said previously you really need to locate the wiring centre and motorised valve and then check the wiring and valve operation
If you are not familiar with heating systems some useful info can be found here Y Plan central heating system - https://www.flameport.com/electric/central_heating/heating_wiring_Y_plan.cs4

HW 'on ' should normally connect straight to the cylinder stat. Stat should then go to motor of valve.
At first sight, it look kike a break in the prog. to stat wire somewhere.

No heating cables altered. Yeah I’m wondering if there’s a JB under floor for all the terminals that I’ve not found yet. There’s every chance a cable could be loose as when I was working under the kitchen floor there was hardly a clip in sight, between me & plumber being under floor cables would almost definitely been pulled. By the plumber of course! ?

 

[brianmoooore]

Before pulling things apart, I'd do an IR test on the 'HW on' wire in the programmer and the live in to the stat (just to check that a broken wire isn't touching something it shouldn't), and then connect a temporary wire between the two to see if the water heating then works.

 

[SSE]

Got to the bottom of this...wasn’t an electrical problem. Very strange setup. So when you turned on HW it fired on the Baxi, when you turned on CH it fired the pump up. The stat was disconnected, it must have been in there from the previous system, would have just been a fire so that explains why there was no power there. Plumber noticed there was 4 pipes coming from the Baxi, two for heating & two for hot water. That’s why there was no valves. Anyway, the pipes coming from fire to cylinder were blocked with thick black sludge. Plumber got it cleared out & that solved it. Thanks for the help although chaps.

 

[PEG]

Hi,it sounds like the hot water is on a gravity loop...this is something that plumber should have noticed right at the beginning,as it has important implications,regarding fault finding and alterations.

It does demonstrate the problems in domestic work,with one job leading to another ?