baxi 105e luke warm water when taps on full flow

[mr_sj]

noticed my boiler only producing luke warm water when using the shpwer/bath or bathroom sink tap.

after some trouble shooting ive found that if any tap or shower is on full blast i only get luke warm water around 50 degrees and it wont get any hotter, if i reduce flow rate to around half the temp suddenly shoots up to full and maintains it no problem, then if tap is turned up again the temp drops back off.

even with the water temp dial on the boiler switched to full i still get the problem, obviosuly something to do with the extra flow rate and the boiling not being able to produce the hot water but no idea what would be causing it and how i can rectify it.

have looked through the baxi manual but cant find anything specifically pinpointing this problem, any help appreciated !! thanks

 

[ddk]

possibly a scaled up secondary heat exchanger or dodgy/scaled domestic hot water sensor

 

[mr_sj]

ok thanks, will it be obvious upon checking them that that is the problem ? if 'scale' is the problem, is it just a case of removing and descaling ?

 

[mrgas]

Sounds fairly normal to me!
Has it always been this way?
Remember incoming water is colder in winter and any combi can only heat up so much water at a time

 

[twgas]

maybe you've got too much water coming out the taps , i think 12litres/min gives 35° rise, 14litres/min gives 30° rise.

 

[mr_sj]

its never been a problem before, usually in the past even with tap on full the temp would be fine. not sure how fast the flow rate is, the shower seems to be ok, not really hot but fine but main problem is filling the bath and it being luke warm.

i'll just use taps at around half way at the moment to make sure water is hot enough.

 

[baxpoti]

i only get luke warm water around 50 degrees and it wont get any hotter

50°. I certainly wouldn't call that luke warm!

 

[twgas]

i only get luke warm water around 50 degrees and it wont get any hotter

50°. I certainly wouldn't call that luke warm!

I assumed that was 50°F

 

[TheAllenFamily]

noticed my boiler only producing luke warm water when using the shpwer/bath or bathroom sink tap.

after some trouble shooting ive found that if any tap or shower is on full blast i only get luke warm water around 50 degrees and it wont get any hotter, if i reduce flow rate to around half the temp suddenly shoots up to full and maintains it no problem, then if tap is turned up again the temp drops back off.

even with the water temp dial on the boiler switched to full i still get the problem, obviosuly something to do with the extra flow rate and the boiling not being able to produce the hot water but no idea what would be causing it and how i can rectify it.

have looked through the baxi manual but cant find anything specifically pinpointing this problem, any help appreciated !! thanks

Hi there,

I have the same problem. Did you manage to resolve this and, if so, how?

Thanks,

Geoff

 

[powell30]

TheAllenFamily, open a new post.

Most likely cause is scale. Remove the Heat/ex and sensor and descale or replace them and keep the old as spares......and fit a whole house limefighter otherwise you will have the issue again....and again....

 

[bazt100]

Hi Mr_sj
did you get to the bottom of your issue with having to reduce your tap flow rate to get hot water?

if i reduce flow rate to around half the temp suddenly shoots up to full and maintains it no problem,

I have a similar issue and its driving me mad

 

[Thedonk]

HI - wondered if you had sorted the problem out with your luke warm water. I have same boiler and same problem and wondered where to start.

 

[freddy871]

Old post I know ,,, but did any of the sufferers manage to cure the problem of luke warm water.. I would be interested to see if the offered remedies cured the issue.

 

[petit_pablo]

Yes dont turn the tap on so fast in winter

 

[freddy871]

i see your point ,, however after further investigation have now found that CH flow pipe gets hot on DHW demand.. so isolated CH flow/return and turned tap on full ,, surprise surprise piping hot water.. now found a thread on here from Puddle around stuck diverter and how to dismantle clean silicon grease and refit.. worth a go.. even gives link for replacement DV replacement actuator bush.... will let you know how I get on.. Link to puddles thread below for ref....

http://www.ukplumbersforums.co.uk/central-heating-forum/24313-baxi-105e-hw-problem.html