Boiler does not fire up on demand - Follow up

[DP]

reeds

Not reeds but micro switches,
You need to read up on Y plan wiring and operation

 

[DP]

Same principle.

Very different operation.

 

[BlueLoo]

I could dig out the technical drawings for the thing and quote part numbers if it would make the Pedants happy!
Its a motorized valve with internal NO/NC contacts

Point is; the motor closes the circuit which energizes the boiler. Somert is likely amiss with that bit.

Sheesh.

 

[DP]

Fair point, and I will probably do that, thanks.

get a multimeter. Trace the black wire where it goes. Open the box, you will see mass of cables. On second thought, get a pro in. Difficulty here is that plenty ‘heating engineers’ stumble on faulting Y plan.

With hot water off and heating off, pointer on the valve is at H
When you switch on the heating, does that pointer move to mid position

 

[BlueLoo]

I'd agree on getting a pro in. There are better occasions to learn about 240V AC

 

[DP]

I could dig out the technical drawings for the thing and quote part numbers if it would make the Pedants happy!
Its a motorized valve with internal NO/NC contacts

Point is; the motor closes the circuit which energizes the boiler. Somert is likely amiss with that bit.

Sheesh.

Open forum, you can write what you like but knowledge of item in question over rides assumed operation. When did you encounter a reed switch that will switch 2 amp inductive load directly. You are unlikely to find such a reed switch

 

[BlueLoo]

Open forum, you can write what you like but knowledge of item in question over rides assumed operation. When did you encounter a reed switch that will switch 2 amp inductive load directly. You are unlikely to find such a reed switch

I haven't.

Being specific, a reed (switch) is usually (?) magnetic isn't it?
But its a term of phrase and in this instance means nothing.

Obviously.

 

[DP]

Reed switch is sometimes found in hot water flow switches or pedal switches, Level switches etc

 

[Tanel]

If the valve is moving between all the correct positions as the controls call for then it is the valve microwswitches that are faulty, the actuator head just clicks off no need to drain anything, you just push the little black release button at the opposite side of the position indicator and it just pops of get a replacement, and get one of these,

https://www.ebay.co.uk/itm/363561488945?hash=item54a5f41231:g:qwUAAOSwkr1hVZwR

Turn the power off to the heating system and cut the existing wire and connect to one end and the new valve to the other end and plug them together and turn the power back on, pop the new actuator on , it just clicks on, and job done, the connector will save you going into the wiring centre which I wouldnt recommend you do

Cheers Ian, it's starting to make sense! I'll check out that link, thank you.