CH fault with Baxi 133 he plus

[sputnick]

Hi all so I'm having nightmare with a customers boiler. Intermittent fault on CH hot water works fine every time. No fault lights, so rooms stat calling for heat ,clock on, pump runs and that's it. I have checked both flow and return thermistors both have resistance within the range in book (about 6). I've checked that there's 240v on electrical block from internal timer on all relevant terminals. Boiler works fine for a few days and then stops and won't fire up on heating but never goes to lockout. Motorised valve head has been changed and made no difference. Occasionally boiler will fire up but then goes out after 20 seconds again only when heating is on. So does anyone have any suggestions I'm struggling as it rarely goes wrong when I'm there. I thinking pcb but would like a better diagnosis if poss. Cheers Nick.

 

[Dotty]

Need you to get 8 more posts under your belt, Nick, then send a PM (Private Message) with your gsr details to either Gas man - View Profile: gas man - Plumbing Forum | Plumbing Advice | Plumbers Forums | A forum for plumbers advice in the UK or Redsaw - View Profile: REDSAW - Plumbing Forum | Plumbing Advice | Plumbers Forums | A forum for plumbers advice in the UK who will check you and then give you access to the gsr private forum.

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[Dotty]

Opening thread back up and moving to private forum.

 

[diamondgas]

Did you sort it out sputnick?

 

[sputnick]

No trying to get back this week customers been away but have try and resolve it. Im thinking it may be the actual divertor valve/body I've never changed one of theses but someone said I need a key to take it out???

 

[JBP Heating]

Just an allen key I think sputnick, for the valve body. Might be wrong. Have you checked the flow sensor. Have known these to stick. Have also known the diverter to fail though.

 

[arran197]

Ye, I'd be checking the flow switch too. From what you have described it's running the pump but the flow switch isn't proving.

 

[Ermintrude]

Didn't read. Wrong boiler !

 

[diamondgas]

Just checked the mi's on this boiler, never seen one in my life! However I'd be looking at what aran197 has mentioned as I'd assume that the heating flow has to be proven before the boiler ignites ... could be a dodgy microswitch on it ? Just guessing mind 🙂

 

[kennedy1978mark]

.....

 

[Billy Bob Bob]

I've had this fault on a duo tec 28 he and it was the Pcb , very intermittent .. It done my head in so I tried a board from a boiler i knew was ok and it has been spot on since !

totally different boiler to the duotec,theres 15 years between them in technology,the duotec works the 133 was s###

 

[diamondgas]

totally different boiler to the duotec,theres 15 years between them in technology,the duotec works the 133 was s###

It looks a bit like a hybrid ... combi guts slung under a solo 🙂

 

[Billy Bob Bob]

It looks a bit like a hybrid ... combi guts slung under a solo 🙂

yep into a solo HE if you ever get asked to work on one Steve refuse this is the one where the burner can suddenly fail and melt the ali hex

 

[Billy Bob Bob]

this is said nightmare [DLMURL]http://www.freeboilermanuals.com/pdf/baxi_disc/Combi-HEplus%2080,100%20&%20130.pdf[/DLMURL]

 

[Kev the gas]

This model had a metal filter on the central heating return pipe, inside the return connection.

I would check this before replacing any more components.

 

[diamondgas]

yep into a solo HE if you ever get asked to work on one Steve refuse this is the one where the burner can suddenly fail and melt the ali hex

Cheers Mark... Hopefully I'll not ever see one 🙂

 

[JBP Heating]

They are nasty boilers. There are a few dangerous faults that can occur with the burner and hex even if they're looked after.

Can we post vids on here?