Problematic Baxi105e

[johnscarlet]

Hi all , first post on this forum , have been a long time lurker , some great info and reading here . But now have a need to post . Be gentle

Some background .
My boiler is a Baxi105e . Its the only gas appliance in the house .
The CH works fine , always has . The stat calls for heat and the heat cometh.
The HW on the other hand is tempramental . We get about 15 seconds of hot water (but not so hot that you can't keep a hand under it , even with the boiler set to max) and then the gas cuts out . It then cuts back in , and then out again . Never reaching the original temp when first turned on . In the time I have been in this house , its never been right , although not as bad as it is now . The flow rate from the bath mixer is about 10l/min, under the boiler max I believe . The boiler itself has been serviced a couple of times , this problem was pointed out at both servicings but no solution was forthcoming , and had had the whole diverter valve replaced (not just the diaphram, although that appears to have failed again ( towel radiator getting warm when DHW running) .

Couple of other points .
-I get no fault lights blinking at all . the lights come on when they should and off when they should
-I live in a hard water area ( could the H/EX be scaled up ?)
-The HW control on the front of the boiler seems to have very little control over the output temp , but when turned all the way down there is no HW

I know its going to result in a Corgi Engineer call out , but if I could get an idea of what might actually be wrong it would be great

Cheers
John

 

[ChrisR]

could the H/EX be scaled up

Yes, primary(boiler) side, not so likely tap water side.

10l/min is correct ( to give you hot enogh water for a bath.)

Clean or replace the secondary heat exchanger - not too expensive for thise iirc.

Do a search on sludge, powerflush, magnaclean ...

Worth checking the sensor too.

 

[johnscarlet]

Cheers Chris , I thought that might be the case .Have been doing a lot of reading before posting . Have got a guy coming out tomorrow . Have also checked out the Magnaclean / boilerbuddy info . Its funny , I have searched baxi / 105e often , but couldn't see anything similar , search for Magnaclean and i find another baxi with a similar problem but with no HW at all . We are not to that point yet

Thanks

John