Baxi 80 HE Instant combi hot water issues

[Allgoode]

Hi all,
I am sure i had previously posted regarding this boiler & issue with customer getting hot water for shower/taps, etc.
Basically if they want a hot shower they have to turn on basin hot mixer tap full for couple of mins before steady hot flow occurs.
They then turn on shower & it maintains temp & regulation.
If turning on shower then initial splurge of warm water & then drops off to cool/cold with occasional warming.
Other plumber changed diverter diaphragm about 5 months ago to no avail & they have just managed & got by with work around.
Looking for some advice on this to finally get sorted for customer.
If i have already posted on this & am being daft please point me to original post,
Thanks,
Andy

 

[masons]

you need to change the venturi in the right hand hydroblock and you problems sorted also check burner pressures

 

[Allgoode]

You mean the inlet venturi on the valve 3 way assembly pt no - 248727 that has the diverter valve motor?
This the one with the inlet filter assy?
If this fixes it i will be well chuffed,
Thanks,
Andy

 

[masons]

in right hand hydroblock need 24mm spanner to access (pt 248051)

 

[Allgoode]

Just an update albeit a tad late.

I changed the inlet venturi first. Old one was in bits & gave filter a good clean but didn't fix.

Worked back stripped out pressure differential valve, rear section seized solid but front section had smooth movement on pin.

Changed complete assy as had it out. Bit of a pig to work on though.

Also changed 3 way valve diaphragm for new genuine baxi one & checked pin operation, all ok.

Had other snags with new leaks on boiler due to the age of it but sorted with minimal swearing.

All working sweet now & old couple very pleased.

Hope this helps anyone in future.

Cheers.

Andy

 

[Harvest Fields]

Just an update albeit a tad late.

I changed the inlet venturi first. Old one was in bits & gave filter a good clean but didn't fix.

Worked back stripped out pressure differential valve, rear section seized solid but front section had smooth movement on pin.

Changed complete assy as had it out. Bit of a pig to work on though.

Also changed 3 way valve diaphragm for new genuine baxi one & checked pin operation, all ok.

Had other snags with new leaks on boiler due to the age of it but sorted with minimal swearing.

All working sweet now & old couple very pleased.

Hope this helps anyone in future.

Cheers.

Andy

And how much did all that set them back? got one with the same issue

 

[Allgoode]

Ended up just under £300 all in which is just below fixed price repair by baxi.
Spare parts were bought from plumbcenter & not as keen as online.
I would definitely make sure you have spare 3/4 seals & some good spanners/adjustables for getting to some of the pipes.
Also a spare auto air vent is a must as most will be blocked or have seeped some time in the past & have been closed making the refill & bleeding a pain in the bum.
Thats about it, just follow through logical sequence oh & before i forget a box of plasters for your fingers/knuckles....
Cheers,
Andy