Old system playing up

[Dan hart]

Hi all

I'm new here so thanks in advance, I have an old Netaheat boiler set up (gravity fed) which failed to fire up for central heating last week, I have set the three way diverted valve to manual and have been using the "call for hot water" to heat the radiators (once its been on for half hour and nice and hot I do get nice hot water pouring into the expansion tank) so want to get this resolved asap, tonight I bought a full Honeywell v4073 and swapped out the head, however, this hasn't remedied the issue, the spindle still seems loose enough (can turn by hand) my thermostat (old wired type - non digital) is set to full and clicks in and out & the controller (old lifestyle Lp722) led come on when I advance for central heating with nothing happening elsewhere.

I have removed the new valve head from the brass valve itself to see what happens when I switch from call for hot water/call for both/call for central heating only and it does nothing.

It is most likely that
A. The new valve head is duff
B. The controller is duff
C. The thermostat is knackered
D. Other

It has all previously worked well so I doubt a wiring fault, I'm skint and a well experience diy'er & would never mess with gas FYI, just after a few pointers to narrow the fault until I hav to go cap in hand to relatives for plumber money!

Thanks

Dan

 

[Last Plumber]

Hello Dan and welcome!

It sounds like you have a couple of issues.
Has the water always poured into the F+E tank after half an hour?
What system do you have, Is it a Y plan ?

 

[Dan hart]

I believe it is yes, small header tank in loft, 3 way Honeywell diverter valve (22mm) and cylinder in airing cupboard with grundfos pump.

I don’t believe the hot water ever expanded into the tank before this fault but I rarely went in the loft, I have never heard it before certainly!

 

[Last Plumber]

Are you any good at electrical testing?
Do you have a multi-meter or Voltage tester?

 

[Dan hart]

Yes I’m not bad, I’m no sparky but used to work on 240 & 3 phase in the past, I have a couple down the shed collecting dust I can use.

What do you suggest?

Thanks by the way!

 

[Last Plumber]

If it's wired as a Y plan. You should have a 240V on the white wire to the Honeywell Valve when the Programmer is calling for heating and the Room stat is closed (calling/on).

This is a wiring diagram for the system. If it is wired as a Y plan that is!!

 

[Last Plumber]

Can you see that picture?
It looks blurred to me but it could be how I'm looking at it!

I have to say at this point, I am definitely not responsible if you electrocute yourself, Suffer an electric shock, set fire to anything etc.

You need to work safe ! if you are in the slightest bit unsure. You are very strongly advised to seek professional help!

Preferably from a Heating Engineer.

 

[Last Plumber]

If you cannot see it. Google Y plan wiring.
Do you have a photo of the area with the pump, valve and pipe work etc?
It may help

 

[Dan hart]

If you cannot see it. Google Y plan wiring.
Do you have a photo of the area with the pump, valve and pipe work etc?
It may help

 

[Dan hart]

I can see the wiring diagram fine, may take me a while to work out the lovely connection box though!

 

[Dan hart]

Okay, there’s a total of 7 wires into the connection box.

1. Valve
2. Immersion heater
3. Pump
4. Controller
5. Switched live (isolator)
6&7. Flat 3 core wires coming out of the floor.

 

[Last Plumber]

Very neat!

Is there live on white when Heating is calling or have you not got that far yet

 

[Last Plumber]

1. Valve
2. Immersion heater
3. Pump
4. Controller
5. Switched live (isolator)
6&7. Flat 3 core wires coming out of the floor.

1 = Valve
2 = Cylinder stat
3 = pump
4 = Programmer
5 = Switched fused spur
6 & 7= ? Room stat?? maybe a frost stat??

 

[Dan hart]

This is the wiring set up

 

[Last Plumber]

The white wire from the valve. Is there 240V on it when the programmer and room stat are calling for heat?

Check it on AC Voltage. red probe on white and your black probe on the Blue from the valve.

 

[Dan hart]

The white wire from the valve. Is there 240V on it when the programmer and room stat are calling for heat?

Check it on AC Voltage. red probe on white and your black probe on the Blue from the valve.

No, just checked

 

[ShaunCorbs]

are you getting voltage out / from the prog (heating)

also are you using the volt sick in the photo instead of a multi meter?

 

[Last Plumber]

You need to check the programmer is giving out 240V on Central Heating on terminal.
You could disconnect the wire in the box and test if it becomes live

(as Shaun said above, if you are using a volt stick/pen thing for this job, it will not do)!

 

[Dan hart]

are you getting voltage out / from the prog (heating)

also are you using the volt sick in the photo instead of a multi meter?

The stick was just my tester when I changed the valve head, I’m using a proper meter to test, 240 coming in for on fixed spur

 

[ShaunCorbs]

If you have from the prog on the heating side when it's on 240

Do you have 240 going to and out from the room stat ?

 

[Last Plumber]

Test that you have a neutral!
test between permanent live and the neutral that the valve is wired to (blue)

 

[Dan hart]

You need to check the programmer is giving out 240V on Central Heating on terminal.
You could disconnect the wire in the box and test if it becomes live

(as Shaun said above, if you are using a volt stick/pen thing for this job, it will not do)!

So just to check, from my list of connections above, heating on (from controller) would be connection 1 on my bit of paper?

 

[Dan hart]

Test that you have a neutral!
test between permanent live and the neutral that the valve is wired to (blue)

Yep, I have a neutral

 

[Last Plumber]

I can't see where the wires go.

I think the wire from the Programmer goes to red on the flat 3 core. The same one that has a yellow connected to the White from the valve?

If that's correct then the wire should become live when you switch heating on

 

[Dan hart]

If you have from the prog on the heating side when it's on 240

Do you have 240 going to and out from the room stat ?

240 coming in, no change in voltage at when thermostat is above/below room temp click, nothing on the yellow wire either

 

[Dan hart]

I can't see where the wires go.

I think the wire from the Programmer goes to red on the flat 3 core. The same one that has a yellow connected to the White from the valve?

If that's correct then the wire should become live when you switch heating on

Yes that powers to 240v when I call for heating and powers down when ch is switched back off

 

[ShaunCorbs]

wiring dia for your stat on the inside of the cover ?

 

[Last Plumber]

With the Heating on and stat turned up, test the red and blue then test the blue and yellow

 

[Dan hart]

wiring dia for your stat on the inside of the cover ?

 

[Last Plumber]

Let me know what you get?

 

[Dan hart]

With the Heating on and stat turned up, test the red and blue then test the blue and yellow

Red + blue = 240v
Yellow + blue = 2v

Stat set at 30, heating on

 

[ShaunCorbs]

turn the power off

move the yellow wire to no 1 terminal (eg red and yellow together)

heating should start

 

[Last Plumber]

Stat broken.

Power off, put yellow onto red terminal, with red still on there, Power back. You will have linked out the stat till you get a new one.

 

[Last Plumber]

Shaun is steeling my Thunder !

 

[ShaunCorbs]

Shaun is steeling my Thunder !

no thor im not