Vokera Linea 24 Temperature Fluctuating

[Dazzh]

Hi,

Looking for some advice please.

I have a Vokera Linea 24 gas combi boiler which is 13 years old.
Recently while running hot water the temperature has been fluctuating. Basically what happens is when water is running it heats up to 61 degrees and then the flames in the boiler go out. The water temperature drops to 55 and the boiler reignites. It reaches 61 and then goes out again. It continues doing this until the HW is turned off. When turned off the temperature displayed is 78 and then it starts to drop.

Any ideas on what could be causing this and the part that is required.

I'll probably get someone in to replace the part but dont want to be paying for things that I dont really need.

All help appreciated.

Thanks

Jim

 

[45yearsagasman]

Plate heat exchanger is the most likely culprit. They can be cleaned, but a new one may be the best bet. Also make sure your system water is clean, and if not sort that out as well.

 

[Dazzh]

Hi Pete,

Thanks for the reply. If I was to change the heat exchanger is there any other parts that would be as well changed when it was getting done.

When I look the part up it shows thermistors as recommended also is it worth doing these also.

Thanks

Jim

 

[McCombi]

I wouldn't go buying any parts yet, you said when water turned off the display reads around 78 degrees, this would rule out plate hex as display would be around 90 degrees.

Sounds like another common problem on these, but it will require a qualified rgi to fix I'm afraid as its combustion related.

If you don't know a reliable engineer, there's a couple from Glasgow on here frequently who seem to know these boilers inside out, maybe they will see this and help.

 

[ianmcd]

As Brassedoff correctly says, its unlikely to be the plate heat exchanger , you are in a soft water area, and I agree that it is more likely to be the v****** but we are not allowed to give this advice on here and as you are not gas safe registered you would be breaking the rules by repairing this yourself, not an expensive repair though and a decent engineer will sort you out no problem

 

[Agile]

78 C still seems rather too high to me! I would prefer to see about 65 C.

Soft water does not prevent debris in the system side.

It really needs to be taken apart and inspected and the plate cleaned anyway as well as checking the pump impeller.

I have a feeling this boiler has not been properly serviced in a while?

Tony

 

[ianmcd]

78 C still seems rather too high to me! I would prefer to see about 65 C.

Soft water does not prevent debris in the system side.

It really needs to be taken apart and inspected and the plate cleaned anyway as well as checking the pump impeller.

I have a feeling this boiler has not been properly serviced in a while?

Tony

Maybe you should actually read Brassedoffs post Tony as he is correct if the plate was blocked the primary temp when the demand for DHW has ceased would indeed read 90C or above,

 

[Dazzh]

78 C still seems rather too high to me! I would prefer to see about 65 C.

Soft water does not prevent debris in the system side.

It really needs to be taken apart and inspected and the plate cleaned anyway as well as checking the pump impeller.

I have a feeling this boiler has not been properly serviced in a while?

Tony

Hi

Boiler was serviced Feb of this year.

Appears to be a few different views on the problem. However was just trying to ascertain if it would be a common problem with a reasonably inexpensive fix. Had no intention of doing any repair myself as don't like to mess about with anything to do with gas.

The temperature dial is set at half way at this time. I turned it up to full and then when hot water is run it reaches 63. When tap is turned off temperature reads 85.

As stated boiler is 13 years old, if fix is too expensive it may be the case that it would be better to get a new boiler.

I'm in Ayrshire is there a list of recommended tradesmen in the Forum.

Once again thanks for your replies.

Jim

 

[ianmcd]

No Jim you do not need a new boiler, your old Linea will do you fine just needs a proper strip service not a clean out which is what you have had, we are not allowed to advertise on here so if you want to PM me I can sort you out

 

[Dazzh]

No Jim you do not need a new boiler, your old Linea will do you fine just needs a proper strip service not a clean out which is what you have had, we are not allowed to advertise on here so if you want to PM me I can sort you out

Cheers Ian.

Have sent you a PM.

Thanks very much for your reassuring advice and to those others who have taken the time to reply to my post.

Jim

 

[Agile]

We all know that it is a lack of heat transfer to the hot water.

There can be several causes of this, often caused by dirt or a weak pump.

Different people will put forward their best guesses.

Often its a combination of problems!

Tony

 

[petit_pablo]

Blocked plate heat ex.

Linea's are prone to it. 78c is too high a flow temp on HW demand.