Boiler not firing, no H/W or C/H

[matt1e]

Ok. FCU to boiler on. Water and CH set to constant.

At Boiler:
230v between ON and Live.
0v between ON and Neutral.
0v between ON and Earth.

then you don't have a demand at the boiler then
the fault lies with the external controls

Matt

 

[adam1984]

The SL from room stat goes to the 10 way j/box. it is connected in the connector strip with the white cable from the sundial Y diverter.

 

[matt1e]

Will anymore photos help out?

A one of the wiring centre might help but only if the photo is large enough to see

 

[adam1984]

what do you mean by external controls?

Pump / Room Stat / Diverter?

 

[furryneddy]

The SL from room stat goes to the 10 way j/box. it is connected in the connector strip with the white cable from the sundial Y diverter.

as mat1e said good photo will help

 

[andytw]

The SL from room stat goes to the 10 way j/box. it is connected in the connector strip with the white cable from the sundial Y diverter.

This is your reference point !! I would rest here for a while.
If you measure between this connection and neutral you should have 220 v when the room stat is turned up and 0v when the room stat is turned down.
When the room stat is turned up and you have 220v, as described, then the diverter valve should activate. Can you hear it moving ? Only when the actuator on the diverter valve moves to the correct position will it hit the microswitch which will then send mains to the 'On' terminal of the boiler.
It is sounding like the actuator is faulty. (IMHO)

andytw

 

[plumbplumb]

Re my earlier post.

orange and white wires are found on the mid-pos valve
mid position valve wiring. CH turned on

White wire to earth/neutral (230v) indicates heating demand to valve
Orange wire to earth/neutral (230v) indicates power to pump/boiler

 

[furryneddy]

Re my earlier post.

orange and white wires are found on the mid-pos valve
mid position valve wiring. CH turned on

White wire to earth/neutral (230v) indicates heating demand to valve
Orange wire to earth/neutral (230v) indicates power to pump/boiler

So if you go back to the boiler you should have two "lives" now going into the boiler wiring terminal one from the spur to power boiler/programmer and one switched to fire it up

 

[adam1984]

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[adam1984]

Re my earlier post.

orange and white wires are found on the mid-pos valve
mid position valve wiring. CH turned on

White wire to earth/neutral (230v) indicates heating demand to valve
Orange wire to earth/neutral (230v) indicates power to pump/boiler

Done as above.

White - earth = 230v
Orange - earth = 0v

 

[adam1984]

Problem located.

its the Sundial Y Diverter.

I took the cover off and had a poke about with the actual mechanism and it appears like it has stuck. with a screwdriver placed on the actual mechanism i am able to give it a little flick and the biler and pump fire up.

Is it possible to change parts or am i looking at a new diverter? ref is Honeywell V4073A

 

[furryneddy]

All the parts are available as spares

 

[adam1984]

ok. I have a plumber coming tomorrow to look at it. I will call him in the morning to see if he can replace parts rather then the whole thing.

 

[furryneddy]

ok. I have a plumber coming tomorrow to look at it. I will call him in the morning to see if he can replace parts rather then the whole thing.

Well if he can't replace the head show him the door....

 

[andytw]

You can buy other makes that are interchangeable with the Honeywell. My advice is don't go there, make sure the new one has Honeywell written on it.
You just need the actuator replacing. It is actually quite a straightforward D-I-Y job.

andytw