Ideal isar HE 30 +programmer XF 2008

[kenaba]

HI all i need some help
DHW was only running at a trickle but central heating working fine A week later i came down in the morning to find the boiler dead no lcd display
called british gas engineer out he said there were three faults
Diverter valve leaking and probably stuck in CH position
pcb failed
user control failed he tested to check there was 240 volts to the boiler and removed the diverter valve motor head.
If the pcb has failed will the user control have failed also
In the installation and servicing manual an lcd fault HE is a pcb error but in my case there is no lcd display to indicate any error
What checks can i get my electrician to carry out to establish the pcb and the user contol is faulty as these are expensive parts

 

[plumbplumb]

If there is power into the boiler and to the pcb but there is no display on the user controls then it's PCB which has failed.
It is unlikely that the user controls have failed.
HE and LE indicate pcb error as does no display.
I have repaired more of these than I can remember with this fault.
Never swapped a user controls.

 

[dcawkwell]

Ideal Isar best place for them is nearest skip.
Change it now. The breakdown is an ideal opportunity.
Repairing this one is going to be expensive.

 

[kenaba]

Thanks plumbplumb and dcawkwell for your imput
I checked the power to the boiler and pcb both are ok,before fitting a new pcb I need to know what caused the pcb failureI spoke to CET LTD who do an exchange scheme and the guy there told me that sometimes the fan can knock out the pcb Is this possible?I don’t want to fit a new pcb only for it to be immediately knocked out by the fan if the fan is faulty or has he got his facts wrong I would like to know what could have caused the fault could it have been the diverter valve which wasn’t working properly which will be replaced before switching on boiler. Any possibilities?
My next question concerns the diverter valve cartridge in my installation manual it says part no 174814 but the updated manual says 175411 there is also 174200 grey top 173967 red top if I take the motor off will I be able to tell or have I got to remove it .
Your input will be much appreciated

 

[plumbplumb]

As soon as you take front cover off the boiler the diverter valve is in front of you on the left hand side towards the bottom. It's a square box.

It will be evident if it's the grey or red topped diverter valve head. They are not interchangeable.
If you see the colour of the valve head you will know which cartridge is required.

The grey top had a button on the left of it which you pressed and twist the valve head about 1/8 of a turn to pull it out. Red top had a circlip underneath to remove it.


On the original M series boilers the fan did used to take the PCB out and you had to change both but on the HE series the fan was updated.

If your PCB is the old black type they were notoriously unreliable and were updated to the orange (V9) pcb.

 

[engineerman]

you have the isar with the brass manifold it will be a black headed diverter not red or grey

 

[kenaba]

Update before I came back here to your posts plumbplumb and engineerman I took the decision to fit a new fan anyway as it's three and a half years old and didn't want to take a risk on the pcb
Have ordered all the parts now and await delivery after easter
By the way my pcb is orange You were right engineerman the cartridge is the black top one part no 175411 I rang Ideal to check.
I will come back here when I start the work If need advice

 

[engineerman]

why did you order parts????/
spend a few quid on a good rgi would of saved you money on parts,
he would of diagnosed the fault
you should never go on the internet on how to fix your boiler
get to know a decent rgi would be better or a fixed price repair would of been cheaper

 

[kenaba]

Engineerman read my original post british gas engineer diagnosed the faults i needed a new pcb and diverter valve cartridge anyway regardless of what engineer fits them. getting a new fan will save another call out charge the fan was getting a little noisey anyway

 

[MJN]

You've done the right thing. The new fan can always be kept as a spare or resold if you find it's not the culprit. Indeed keeping a few likely-to-go spares for the life of the boiler, particularly if you can get them at reasonable rates on an opportunistic basis, can prove most worthwhile if/when it breaks down in the midst of winter when paying someone to visit can be very costly even if you can get someone at all.

The items used or as-new value tends not to depreciate so you can recoup costs (or even make money!) by selling them on afterwards. This strategy has saved me a packet, or indeed possibly even just about made me money, over the years.

Let us know how you get on!

Mathew

 

[kenaba]

HI just to update my post I have taken out the diverter valve cartridge and it seems to work fine pin depresses right to the bottom approxx 10mm I therefore suspect the problem is the diverer valve head.there is no pin protruding but is inside i therefore think it is stuck is there anyway to test this? I did a resistance test on the new fan it showed 110.9 ohms i did the same test on the boiler fan it was 109.9 ohms i saw on another forum it should be not much below 112 ohms so the boiler fan might be ok before buying a new diverter valve head i would like your imput

 

[gwww]

Anything over 100 ohms is fine. When power is turned on the actuator motor self tests moving through both positions. ie The lever on the left side of grey head will move approx 10mm when power turned on and come to rest in dhw (forward) when tap running. No movement it is likely actuator failed. Check wiring plug for moisture damage. HTH.

 

[superman123]

you say the dhw runs at a trickle. what flow rate are you getting out your tap and what is the heat diffs between mains in & hot out, should be 35 degrees. also is the dhw turned up to max on the programmer. you should get a GAS SAFE ENGINEER to check the working presure and also service your boiler it takes me no less than 40mins for a full service., and thats if all is ok, so dont let anyone doit in 15 min waist of time and money

 

[petit_pablo]

Im confused

BG went out to the boiler and told you what was wrong with it but arent fixing it?

You've now ordered a fan you didnt need. How much has it set you back so far.