vokera linea 24 dhw luke warm

25 Apr 2010
Reaction score
United Kingdom
Hello been a while. Got a vokera linea just lukewarm hot. Dhw temp on boiler display reads 42 degrees and no more at 10 lites per min. When you close hot tap temp on display reads 58 degrees. Pipes to diverter manifold are very hot. Diverter overhaul kit has been used but no difference. Any ideas ?

Sponsored Links
Have you checked if the ntc thermistors are in range with a multimeter?

Are the control knobs on the front giving accurate settings? Spindles easily broken potentiometer may only be at low setting but front gives impression it's on max.

Can you measure the temp of dhw outlet pipe leaving boiler to see if same figure as what display temp reads?
42 is not. Bad temperature. What is the inlet temperature. Your boiler can only deliver just under 10l per minute and you are getting that

42 is the hw temperature
58 is the heating water temperature

If the gas pressure was low, hw delivery would be compromised
gas pressures champion etc.

Forgot to mention this is a downstairs flat.

An identical system in every way is in the upstairs flat.

At the same out let but in the flat upstairs the boiler will read 58 degrees and the hot water is too hot to keep your hand under too long.

I services these boilers every year and they have been fine up until now.

Only reason problem was found, tenant complained shower was not hot enough anymore.

The landlord mention that years ago they had same prob on same boiler and the previous engineer changed the DHW heatex.

Any help much appreciated
Sponsored Links
So why do you imagine its anything other than a blocked plate HE ?

In any case your initial thermal survey of the boiler would have indicated the excessive temperature differential across the plate HE.

I assumed you meant display showed 42 but temp at tap was actually lower. Have you checked the flow rate/temp rise? Can't remember exactly but think it should be around 35'c rise @ 11ish litres/minute. 42 isn't a bad temp considering.

I would check that at the taps, could be shower mixer faulty.

Oops I gave u flow rate for 28kw not 24kw. doesn't actually sound like there is a fault if getting 42 degrees from a 24kw at a shower.
Phone playing up . Maybe double post.

Gave u flow rate for 28kw instead. If getting42 degrees from a 24 kw, doesn't sound like there's a problem tbh.
OP, what is the burner pressure or have you assumed it to be correct/ someone else said it is spot on/ or something else.

What is the cold water temperature. In Glasgow, I would say at present it is around 10 degree C. At the hot tap, with HW stat at max (if the shaft is not snapped, and primary not passing to radiators), I would see the digi display show 46 once the HW delivery stabilises.

A few hundred miles further south the cold water will be tad warmer. If delivery is NOT 9.5 l a minute, you will get more water but not 35 degree C temperature rise.

Above is what I would be doing/ not suggesting you have have not done so, but I am just 'thinking' aloud ;)
I am interested also. :eek: :eek: :eek: :eek: :eek:

Rodrigues, whatever you are smoking I would like the same. Who is your supplier :D
I am interested also. :eek: :eek: :eek: :eek: :eek:

Rodrigues, whatever you are smoking I would like the same. Who is your supplier :D

Have a look in the CC mate I thought I had lost it but Vulcan confirms , thought all my years as an engineer had been wasted
Oh you mean the one where the pcb stops the gas valve going full rate and never gets above 42 degrees

due to eec European stuff or something where pcb's are made.

British gas software also confirms this is the case !!

Besides its fixed now n'all

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sponsored Links