Not ideal isar 24he

[hav it]

Hello, Had to re install an isar today, due to boiler being removed from new build 4mths ago due to theft in other houses. Guess what boiler wont fire. It flashing h4, what i think is flue temp sencor, pump runs constant but will not reset. good old ideal

 

[hav it]

any ideas chaps

 

[kevindgas]

H4 is ahigh overheat code usually get this if the water isn't circulating properly has the air vent screw been undone?

 

[gigz]

Check the pumps spinning and make sure heating iso valves are open.

 

[hav it]

valves open and pump running. Is h4 not flue temp sencor there are 2 location depending on model, mine just sits into main hx

 

[hav it]

its got 2 yellow wires from it..

 

[gas4you]

Following the MI's fault finding, it does indeed point to the flue thermistor.

Check ntc resistance values as per instructions.

I have also had this caused by the usual condensate trap/sump blocked God knows why though

 

[kevindgas]

valves open and pump running. Is h4 not flue temp sencor there are 2 location depending on model, mine just sits into main hx

quite possibly true but the only time i've seen it was when boiler overheated due to poor circulation - don't ask!!!

 

[hav it]

yeah i know where your coming from but boiler not fired so no heat.

 

[hav it]

should there be continewity across flue stat.

 

[hav it]

iv ordered stat today, should be ready to fit in morning.

 

[gas4you]

should there be continewity across flue stat.

Yes but only at the resistances specified by the MI's.

 

[hav it]

still waiting for stat