Vokers Linea 24 DHW going Hot and Cold

[Lineaman]

Hi,
I am just looking for a bit of advice about my Combi Boiler. The CH side of it works fine no problem but the DHW side keeps going hot and cold at a constant temp, it ignites at 30oC and cuts out at 44oC then reignites again at 30oC this is a constant fault anyone got any thoughts on this please! Fed up of getting a hot and cold shower tango.

Thanks Andy

 

[Rob]

Plate heat exchanger is blocked on the primary side most likely...

You can replace it but its wise to give the CH a clean to prevent it happening again.

 

[DP]

It is not the boiler that is at fault but state of system connected to it. The sediment in the system now (most likely as mentioned above) resides in the boiler to give you fluctuating hot water. System cleanse would be a start.

 

[alan m 1974]

If im correct the secondry h/ex is virtually impossible to clean out and its a new part needed .I dont like vokera combi's and seem to remember going to one and trying to get the h/water to stay on and after p/flushing it and spending all day making sure it was spotless, i had to change the part and it was ok, but a nightmare job still

 

[gas4you]

Plate heat exchanger is blocked on the primary side most likely...

You can replace it but its wise to give the CH a clean to prevent it happening again.

I agree with Rob on this, very common problem on these.

When the hot water cuts out at 44C turn tap off and I bet display will read 90C (system temp) which is overheat.

I always replace rather than clean.

 

[DP]

I am surprised Alan, as the Turbo, Flowmatic, Excel, Maxin and Linea range componets are well placed for the engineer. It is not for the first time I have removed the P2P HE, tapped it on a piece of timber to shock/ loosen debris and then run it under fast flowing water. Has worked a treat every time. Only did another one last week.

Give me a Vokera anyday instead of an Ideal.

 

[fearn]

Plate heat exchanger is blocked on the primary side most likely...

You can replace it but its wise to give the CH a clean to prevent it happening again.

I agree with Rob on this, very common problem on these.

When the hot water cuts out at 44C turn tap off and I bet display will read 90C (system temp) which is overheat.

I always replace rather than clean.

exact same problem as mine and noticed the the dispaly shows the same
"When the hot water cuts out at 44C turn tap off and I bet display will read 90C (system temp) which is overheat."

 

[bengasman]

Might be worth checking the state of the system before you do the work. If heavily soiled the problem is likely to come back soon in which case a powerflush would be advisable

 

[gas4you]

I agree, had a customer who refused to pay for a powerflush when I replaced his plate he, 6 months later it was clogged up again.

This time he had it flushed.

OP; the problem you are getting is that the heat from the system side is not being transferred to the dhw side due to blockage in the plate he, hence the system side going to 90C and shutting down.

 

[Lineaman]

Hi Again,

Thanks for all your replies sounds like i should get a power flush and a new DHW Heat Exchanger. will give it a try.

Thanks again all for your time

p.s just out of interest can i not just flush the system with some sort of chemical a few times insted of the expensive option of PowerFlushing?

if so what is the best to use and how do i use it

Thanks again from a tight arse

 

[bengasman]

Thanks for all your replies sounds like i should get a power flush and a new DHW Heat Exchanger. will give it a try.

powerflush should unblock your h/e so no need to buy a new one.
powerflush is totally different way of doing it, so no, you can not do just a couple of flushes in stead

 

[Lineaman]

Hi Again,

Thanks for the reply.

Ok i will get a quote for the flushing and see how things go.

Thanks Alot for all your advice

 

[gas4you]

Power flushing doesn't usually clean system side of dhw plate he as the boiler is usually set to ch whilst flushing.

You would have to make a point of setting boiler to dhw for a while to achieve this.