Greenstar danesmoor 18/25 wm

[stani]

Went to boiler, smell of burning, which there was, but more of a very hot boiler. Tried boiler stat did nothing just stayed on full pelt. Replaced stat with new item, still the same,
boiler runs ok but just doesn't shut down.
blue 'Worcester' light doesn't work.
on/off button top left of panel which I believe normally is greenish doesn't light.
if I remove either red or yellow lead from stat then boiler shuts down.
tried both stats with hot water stats opened and closed on heat and cooling.
any one got any other ideas?
please,

 

[Best]

Just wondering did you check the frost stat? Could be faulty and locked on.

 

[Dotty]

How many zones on the heating?

 

[stani]

Best, no frost stat found
croppie, just one, sorry didn't read your question properly

 

[magicno1]

Simple test at the board with a multimeter should get you sorted. Had a couple of boards go down on these before!

 

[stani]

This might be a daft question, but where's the board?

 

[magicno1]

This might be a daft question, but where's the board?

Not at all.
anything connected with boiler electrics these days I call boards just habit. On the back fascia where you changed your stat the connections are in there as you probably know. Just test from there that should give you an idea what's happening. You may have a new faulty stat?????
i have changed one PCB on a Greenstar Heatslave not these of course!

 

[stani]

I've tried the stat with continuity tester, turned off OL turned on 0.000 so presume it works as it should be.

 

[magicno1]

Weird!!!!
the stat controls the burner live only. Sounds like the burner is getting a permanent live somehow????
what external controls are there and have they been wired in correctly???.
if you have disconnected the stat and it stops it must be the stat surely?

 

[stani]

Weird!!!!
the stat controls the burner live only. Sounds like the burner is getting a permanent live somehow????
what external controls are there and have they been wired in correctly???.
if you have disconnected the stat and it stops it must be the stat surely?

You mean "A new faulty part"
thats the only conclusion I could come up with, just wanted to ask before I go off on one with worcester