central heating only comes on with h water, stumped engineer

[doitall]

I think it's critical you get the fire removed, and show us how the boiler is connected.

Off your high horse Tony.

 

[stardanny]

Before i do this i think i will get the boiler serviced and try to find out more info then.

Yes, get it serviced by a gassafe engineer and all will be revealed.

I'm surprised that 4 engineer could not find out what wrong , if i could look at the system, with my own eyes, I can see what wrong with it within 5 mins.

Dia, I reckon the 22mm is the gas supply and the other 22mm is the heating return, tee into primary return ( inside the chimney breast ) that is at the moment a flow pipe pipe to port AB via a pump.
If the heating return connected to boiler return tapping on it own then the heating should work on it own, just wrong piped.
The other 15mm pipe that goes straight to ground floor is the heating flow feeding ground floor radiators but on looking on diagram, from port A pipes goes and tee off to radiators and to return tee, unless op drawing is wrong, that wrong is it?

Dan.

 

[doitall]

Agreed subject to a couple of problems with the theory.

A. I think the one pipe is Gas.

B. I think the other pipe is/was the return, maybe connected to the other side of the boiler.

Problem.

If it is the return and its connected to the boiler, and the other end is connected to port A, Where is the actual htg flow,

 

[stardanny]

If it is the return and its connected to the boiler, and the other end is connected to port A, Where is the actual htg flow,

It shared with flow pipe from boiler ( return tapping on it own, otherside? ) to port AB. Which mean the heating will not heat up at all, just bypassing back to boiler. In op's case, where did radiators get it heat from?

Normally, when changing gravity to fully pumped, the heating flow pipe from boiler flow tapping is removed and capped. The heating blowpipe is then run to port A. The existing gravity flow is then run to pump then into port AB.
From port B to cylinder. The existing gravity return cold feed is capped. The existing F&E pipes is connected onto flow pipe before the pump. The existing heating return is left at it is.

Incorrect pipework. That's my answer.

Dan.

 

[doitall]

But the heating does work when the valve is in the mid position

The pipework is all wrong, and it may be easier and cheaper to re-pipe the lot, from the cupboard to the boiler.

 

[stardanny]

But the heating does work when the valve is in the mid position

The pipework is all wrong, and it may be easier and cheaper to re-pipe the lot, from the cupboard to the boiler.

I know, strange.

Argeed, it may have something to do with op moving cylinder 3 m away from old airing cupboard.

Dan.

 

[doitall]

We know the primary flow and return is wrong. I think the heating flow and return is also wrong (crossed) and certainly not connected to the common return as it should be.

 

[matt1e]

I wonder if this may have been once an old primatic cylinder
new indirect fitted and the pump turned instead of doing it correctly
if it is still a primatic cylinder then the pump is the wrong way around

View media item 43478
it may explain some of the pipework
though there is still obviously problems with flow through the rad circuit
I think it may be time for the op to start reconfiguring the pipework
Matt

 

[bonkersbill]

i will get under the floor to see where these 2 pipes go

 

[doitall]

i will get under the floor to see where these 2 pipes go

You should find them around the boiler.

Also, was there any pipes capped off when you moved the cylinder.

 

[Norcon]

Wonder where that one went too?

 

[doitall]

The missing pipe must be capped.

Perhaps the OP could tell us exactly what he/they did when the cylinder was moved.

There must be a few clues around its original position.

 

[dave18]

Norcon,

I asked this back on page 8 it is a "spacer"

Question I now have is this

He tells us that he has moved the DHW cylinder 3meters down the road,

Look at the picture on page 7 unless he took this before he moved the cylinder or he has moved a lot more than the cylinder,

the feed and expansion pipes from the loft
the pump
the 3pv
flow and return pipes
etc etc.

from the photo it looks as if it has been there for a long time, more than before Christmas when this thread started

no new shiny copper pipe work,

very few straight answers to even simple questions

too many "labeled this wrongly"

something does not seem right to me.

David

 

[Agile]

something does not seem right to me.

David

Like DIY gas work removing a BBU gas fire for a start.

Odd too that we are told that plumbers are stumped.

 

[bonkersbill]

Yes the bit of pipe is just a spacer. Moved the cylinder by lableing all pipes, cutting them and reconecting, in the loft i replaced and moved all water tanks and took all water feeds and vents strait up from new position of cylinder. I have not touched any pipework under the floor. The only capped pipe was the one above port B.

I think you are being a bit harsh with ALL the mistakes, the few i have made have been picked up on quickly, if i had made any serious mistakes the system would not have worked the same as it did before i moved it! I have ripped this house to pieces and rebuilt it so im no mug.