Halstead ace 30kw gurus please help!!

[clemda1]

Hi can I start by saying a big thank you to gasman and croppie for there assistance in getting into this forum.

i'M new to the boiler break down gig so please go easy..

I was called out to a Halstead ace 30kw Combi.
problem is no hot water or heating.

on a heating demand boiler only stays alight for 2-3 seconds then flame goes out.
So when there's a call for heat whether that be hot water or heating. Fan and pump engage APS then proves there ignition electrodes spark gas valve opens we have a flame but it only lasts for few second then goes out.

Changed the the flame sensing electrode. Made no difference. Spoke to a mate who suggested pcb. Customer is on a budget so we ended up getting the PCB reconditioned. The guys put old board on a jig that symulated the boiler sequence and all was ok.

Good for the board but I'm now back to square one. Also tested coninuity across the flame electrode leads. All ok.


Anyone have any suggestions where to look next.

Bit more info.

carried out standard electrical tests. Resistance to earth, polarity and Earth leakage all ok




Sent from my iPhone

 

[ShaunCorbs]

you checked the high limit and ntc probes?

 

[lame plumber]

thermistor on way out?

 

[clemda1]

you checked the high limit and ntc probes?

Hey Shaun, thanks for the interests.

As I said I'm fairly new to this diagnostics lark but learning fast. I was under the impression I could iliminate that these where at fault given the fan and pump run and the gas valve solenoid opens to fire the boiler and we ge a flame. If these where at fault the the boiler would not fire?
I did check them Anyway and got about 14k ohms on the ntc, high limit stat not checked not sure there is one but there is an over heat stat is this the same thing? But if these where faulty would the boiler still fire?

 

[jonnyswamp]

Has there been any electrical work done in the property lately, reverse polarity can cause this

 

[jtsplumbing]

Are you sure that the pump is moving anything ? just because it makes a noise doesn't mean its working, be careful if you call Glen Dimplex charge at 60p pr min.

 

[clemda1]

Are you sure that the pump is moving anything ? just because it makes a noise doesn't mean its working, be careful if you call Glen Dimplex charge at 60p pr min.

Hey JTS, no did not actually check the pump. just felt to see if was vibrating. but is 2-3 seconds of flame enough to activate the high limit thermister to trigger the boiler to shut down? I checked the continuity on the pump and ohms reading were within range. How do you suggest i go about checking the pump?

 

[clemda1]

you checked the high limit and ntc probes?

Hey Shaun, thanks for this.

I checked all the thermisters. But checked them in situe. ie disconnected the leads and tested with multimeter on ohms while cold. Was getting a reading of 14kohms. Should i take them out and test to see if as NTCs ohms reading is decreasing as they warm up?
Also my understanding is if they were faulty this should interrupt the ignition sequence as PCB should confirm this prior to energising the gas valve and spark electrode.
As i stated i'm new to this... just lucky the customer is a next door neighbour he knows i'm fresh but is happy to let me learn on the job as i'm not really charging him much for my time. Just want to make sure i stay safe get it right for him. He's a bit tight for cash...

 

[clemda1]

Are you sure that the pump is moving anything ? just because it makes a noise doesn't mean its working, be careful if you call Glen Dimplex charge at 60p pr min.

Hey JTS happy to call Glen Dimplex. Do they do technical for Halstead?

 

[ShaunCorbs]

Hey Shaun, thanks for this.

I checked all the thermisters. But checked them in situe. ie disconnected the leads and tested with multimeter on ohms while cold. Was getting a reading of 14kohms. Should i take them out and test to see if as NTCs ohms reading is decreasing as they warm up?
Also my understanding is if they were faulty this should interrupt the ignition sequence as PCB should confirm this prior to energising the gas valve and spark electrode.
As i stated i'm new to this... just lucky the customer is a next door neighbour he knows i'm fresh but is happy to let me learn on the job as i'm not really charging him much for my time. Just want to make sure i stay safe get it right for him. He's a bit tight for cash...

it should say in the manual for what temp (water) Resistance is given and no normally they just give a low reading,

and could be giving a 79 degree reading and cutting out at 80 so would only come on for a few seconds

and is pump turning / strong enough

take the center screw out and put a old flat headed screw driver (must be old as could damage the screwdriver ) and put a med to firm push pressure into the pump if you can stop it the pump is gone and a new one is needed

but tbh depending on age of boiler, i would try and get them to replace it (not a very good boiler) as no guarantee on how long it would last after the repair and sinking good money to a bad/ not worth repair