Vokera Linea 28 Comb. Boiler loss of DHW

[kjmcdow]

Vokera Linea 28 Comb. Boiler

Over last few months DHW supply has become unreliable; it gets to 52 oC and then switches off until temp drops to 28 oC, then it reheats. Each cycle is 3 to 5 min. CH seems okay. I suspect that the heat exchanger for the DHW is clogged with limescale, even though the water here in Leeds is not hard. Am I probably correct?

I have just signed up for BG HomeCare 100. The first service is next week. I am expecting that the engineer will spot the problem with the DHW supply. I am just hoping for a reliable diagnosis and reasonable quote to fix the problem. If I don’t like either I have the option of declining and walking away from the contract at no cost.

My questions are: What should the engineer recommend? Removal/ replacement of the heat exchanger, pressure cleaning of the DHW side of the boiler, descaling as well as pressure cleaning, something else? How long should it take and how much should I be charged? Forewarned is forearmed, in my book.

Thanks in advance for any help!

 

[nickso]

if the process will clean limescale (if thats even what you have) BG will probably want to clean the PHE with the sonic machine. i dont know if it does limescale though.

you will probably be quoted £250 for this pleasure. you will get a brand new PHE fitted for far less. see what they say and get someone else to quote for a brand new PHE if that is the recommendation.

 

[fanboy]

I wouldn't wait for the engineer to find a fault i would point it out to him, as it almost sounds like you don't want him to find it so that you can mention it after he's done.

Sounds like plate heat exchanger although never assume the fault.

The engineer will or should check the flow rate of the hot water.

 

[kjmcdow]

Thanks for the input. I'll point out the fault to the engineer.

Flow of DHW doesn't change, it just goes cold.

 

[kjmcdow]

Thanks for the input.

Can the PHE be replaced by a competent DIYer? I've got the schematics off the web.

Cheers

 

[bellairaphon]

have any fault codes come up?

Nath

 

[kjmcdow]

No codes, just problem with DHW - cycles hot to cold during showers etc.

Thanks for the interest.

 

[kevplumb]

Can the PHE be replaced by a competent DIYer? I've got the schematics off the web.

the full mi's are on the vokera site

 

[kjmcdow]

I got the schematics from the Vokera website, thanks for the input, though. Looks reasonably straight forward, right?

No need to drain CH side of system? Just turn of water and electrics and go in with the tool kit. I am also not touching the gas side, right? I don't mind getting wet or admitting defeat, but risking an gas leak is not worth saving a few bucks.

 

[kevplumb]

did you get the sabre sorted GG

 

[glasgowgas]

i`ll `pm ya KP

 

[kjmcdow]

Lookin' forward to the 53rd? Haven't been to Ibrox since I left Partick in the early 90's.

Do you reckon replacing the plate heat exchanger is a job for a DIYer? I hate wasting money. A Yorkshireman is a Scotsman with the generosity taken out.

 

[glasgowgas]

if you follow the MI`s TO THE LETTER you should be ok, but as Fanboy has said your whole system sounds gunked up

better off cleaning whole system, then flush clean, then remove plate hex
clean ch side and water side, button it back up, and bobs yer auntysfanny

 

[kjmcdow]

Problem fixed. Have you guys looked at http://www.justanswer.com/expert.aspx? You could earn a few bob.

 

[glasgowgas]

was it the plate heat ex, after all??