central heating problem

[kenny1]

ideal isar HE24 condensing combi boiler with a Central heating fault.

letter 'C' for “central heating” appears in the window but the light just flashes and fails to ignite the boiler to heat the water, it just sits there for ever

if the domestic water tap is turned on the letter “D” for Domestic appears in the window and the boiler ignites and heats the water, running Hot water working properly.

When the water Tap is turned off the letter “C” for central heating replaces the letter “D” now calling for the boiler to ignite to heat the water for central heating mode. but fails to ignite, Now the HOT water which is left in the chamber from heating the domestic water is expelled into the central heating line

no fault codes appear in the window and the water pressure is set to 1 bar Cold

What could this be

 

[Billy Bob Bob]

a axe coming outta the van,or roomstat or programmer fault

 

[diamondgas]

As Ideal axeman, gasman, says. Chech your stat. If you have a remote stat the batteries may be dead!

 

[kenny1]

Hi no batteries not dead new ones and re programed

 

[kenny1]

Central heating does kick in but just for a few seconds then shuts down

 

[diamondgas]

Kinda sounds like your actuator isn't moving! Does it go from 'd' to 'c' burner light flash then perminent then off leaving 'c' only on display?

 

[Billy Bob Bob]

you need a gsr engineer could be thermister playing up or controls

 

[kenny1]

Kinda sounds like your actuator isn't moving! Does it go from 'd' to 'c' burner light flash then perminent then off leaving 'c' only on display?

Yep thats right

 

[diamondgas]

you need someone to take the case off and check out what model/design Isar you have. they came in 3/4 versions. As The 'axeman' says, a gsr engineer will get you sorted. If probs aren't external...

 

[kenny1]

Diomondgas wrote

Kinda sounds like your actuator isn't moving! Does it go from 'd' to 'c' burner light flash then perminent then off leaving 'c' only on display?

Yes it does

 

[kenny1]

thanks lads for your addvice

 

[diamondgas]

thanks lads for your addvice

You're welcome kenny1.

Bye-the-way just to add a bit confusion, it's more likely an issue with the whole valve than the actuator but you have to check the later first B4 you decide a drain down is needed!

 

[kenny1]

Hi Diamondgas and Gas Man
Thanks for your valued help and guidance much appreciated. I had a bit of time today to look at my Boiler and made myself familiar with its workings from the Installation/Servicing Manuel. My trade before I retired was a Mechanical Engineer but respect that yours is a different field that's why I sort your professional advice.

OK
My first thing is to do a check with the Multimeter on the two Thermistors when my mate returns it
I noticed that the Diverter Valve Actuators plastic indicator on the left side does move without restrictions when the boiler goes through its cycle notice from the drawing on the parts list that the valve seating is assisted on its return by a spring, my experience tells me these on occasions stick or spring snaps.

I am hoping that one of the Thermistors is faulty.

Cheers Ken

 

[diamondgas]

My first thing is to do a check with the Multimeter on the two Thermistors when my mate returns it
I noticed that the Diverter Valve Actuators plastic indicator on the left side does move without restrictions when the boiler goes through its cycle notice from the drawing on the parts list that the valve seating is assisted on its return by a spring, my experience tells me these on occasions stick or spring snaps.

I am hoping that one of the Thermistors is faulty.

Cheers Ken

Hi Ken,

Sounds like actuator is okay if the indicator is moving, it's the grey actuator yeh?

 

[kenny1]

yes, and just tested the Thermistors through a Temperature range tested OK

 

[Billy Bob Bob]

what ohms reading did you get off the thermistors? and are they wet pocket or dry?

 

[diamondgas]

yes, and just tested the Thermistors through a Temperature range tested OK

Okay ... well it's more likely that you diverter is stuck! Turn the power off to the boiler and turn the diverter actuator 1/4 turn (Left I think). This'll disengage the actuator from the diverter (You won't get wet!) .... The spindle inside the plastic valve could be stuck IN! I believe 'in' is hot water only! How confident do you feel about draining a heating system and replacing stuff, refilling and knowing it'll all start up okay? Coz that's where you're heading by the sounds of it :angel_smile:

 

[kenny1]

I am now thinking I may have a fault on my Honeywell HC60NG (R6660D10009 Relay Module, my HCW 80 (room unit) programs into it OK, but my guess now is that the relay module is not communicating with the boiler, but you lads know better than me. mines just an educated guess.

cheers Ken

 

[kenny1]

OK will try no problem with draining the system if necessary

 

[diamondgas]

I am now thinking I may have a fault on my Honeywell HC60NG (R6660D10009 Relay Module, my HCW 80 (room unit) programs into it OK, but my guess now is that the relay module is not communicating with the boiler, but you lads know better than me. mines just an educated guess.

ROFLMAO ... Now then kenny1...... did we not mention this from the start? sheeeeeeeeeeeeesh! you can link out the external components on the plug-in socket under the boiler!

Could seriously be time for someone who knows what they're doin!!!

 

[Billy Bob Bob]

you could link it out to prove it but you need to be confident with electrics

 

[diamondgas]

you could link it out to prove it but you need to be confident with electrics

Patience is a vurtue my friend eh? ... lol . I wonder how much you could get selling this sort of knowledge? *ponder* *ponder* *ponder*

 

[Billy Bob Bob]

i know a doctor coustomer of mine does just that have to ask him how much he earns from it

 

[diamondgas]

i know a doctor coustomer of mine does just that have to ask him how much he earns from it

Hey count me in before BG cottn' on! ... lol

 

[kenny1]

Hi
the valve was OK not stuck................ where exactly is the plug in socket under the boiler Steve