Viessman vitodens wb1a heat exchanger -installer wanted

[holty]

I was once staying in a chalet on a camp site. As I know the owner I decided it to be quicker to feck about and try and provisionally Flush the boiler by just using the mains filling loop and some other simple means. As I just wanted a shower for the weekend without any hassle. needless To say I managed this. If some one finds flushing the main heat ex on one these hard, I'd suggest they try another career.

 

[Beardie]

Thanks holty. Mine is an open vented condenser, not a combi, but is the process just the same.
Thanks to the input and views from you guys I have also now contacted the yourplumber website to seek an opinion , hopefully they will come back to me in the next day I so. Had one recommendation that the guy is good at his job and reviews seem to be favourable.

 

[Dan Robinson]

Don't trust review sites.

 

[Beardie]

He has just responded to say he uses magna cleanse rapid flush and does not think he could do it, but would be happy to quote for another heat exchanger... You guys must be psychic...

 

[Agile]

After reviewing your first post, I need to revise my thoughts on your problem.

Unfortunately, I fell into the trap of assuming that the guy had correctly identified the fault as a blocked heat exchanger.

It still might be a blocked heat exchanger, but until proper diagnostic tests have been done, including a thermal survey, then I see that as not yet diagnosed.

Short cycling is at most a nuisance and is not an urgent problem and you should not rush into anything expensive until the problem has been confirmed.

As we had predicted, few engineers are prepared to clean an HE and prefer to just replace parts.

The HE on yours will probably be so expensive that a replacement boiler would be better sense. Depending on how the flue has been fitted could make it a very short task to replace it.

But not economic to replace a boiler just because of short cycling!

Tony

 

[Beardie]

Well the engineer gas come back with prices. He is prepared to power flush but no guarantee that this will fix the problem. Has quoted £1270 to replace the boiler with another viessmann vitodens or £720 to replace the heat exchanger...
So just one more response awaited from a forum member before I need to make a decision...
This has been my only posting on this site and the experience has been positive. The suggestions and advice have been very fair, considering its all based on a description of a problem and no one has had the opportunity to get hands on.... It must be very difficult to make a suggestion without being able to analyse the setup...

Will provide an update in due course.. Hoping I get a positive result... Hmmm

 

[stardanny]

Short cycling mean heat is not taken away from boiler quick enough?
Did you check the pump? Pump may be failing, slow or clogged?

Daniel.

 

[Beardie]

Thanks Daniel
New pump fitted in April when symptoms first showed.

 

[kidgreen61]

If it's any help, I look after one of these for a lady who has had continual problems brought about by (I think) the installation of 2 crappy heated towel rails which dispense crud into the system quicker than an analogy I can't think of.

I cut into the primaries, and blasted mains water in both directions several times, and was astounded at how much crud came out.

Boiler has worked perfectly since (2 yrs)

As has been said, the HEX is simply a loop of pipe so is easy to clean, so if anybody tells you that you need new this that etc, tell 'em to go forth.

I'm only a few miles from you, but am stacked out workwise otherwise I'd sort it for you.

 

[Beardie]

Kidsgreen61.
Thanks for the offer. Agile was also generous in offering his service and experience and he lives in London...!

My boiler is working albeit at a reduced efficiency and lower temp, so would be happy to take you up if you are ever over this way and work slacks off...

I'd rather get to the root cause than just swap stuff out. ..I still believe in the product and brand having selected it for its unique heat exchanger design...

Just let me know if you think it's a goer taking this on...many thanks

 

[Beardie]

Thanks to this Forum and the experts who responded with advice, my boiler is alive and kicking out heat like new. Agile, holty, kidsgreen61, danrobinson, johnd and others, you are top people. No one local to me was prepared to clean the hex as this forum suggested. Plumbers would not even guarantee a power flush to sort the problem out. The cheapest quote was £720 for swapping out the heat exchanger.

The issue was fixed by stripping the boiler and flushing the heat exchanger. There was nothing in there but magnetite particles that were caked on...they were blocking the flow paddle sensor and were partly blocking the heat exchanger. Some light use of brick acid and a little x800, cleared the exchanger and flow resumed with a water hose to flush out leftovers....all put back, x100 added and now running better than ever....

Thanks again guys...keep up the excellent service...wish every one of you success in your own business...

 

[JohnD]

as you already have a system filter, which ought to be capturing circulating particles, I wonder if Sentinel X900 (which you don't drain, you leave it circulating, with the inhibitor)

http://www.sentinelprotects.com/uk/...tral-heating-systems/sentinel-x900-filter-aid

would help to keep the system clean.

The dirt in your HEX can't have come from the boiler (the HEX is stainless steel), it must have come from residual dirt in your radiators (mostly) and pipes. Presumably the boiler was installed on an old system which had not been thoroughly cleaned.

 

[Beardie]

Hi Johnd, yes when the boiler was installed I don't recall the installer doing a proper flush as such....the particles are definitely from the radiators...I did not know of x900 but will look it up now and consider addition.
Hopefully the sentinel will capture other bits in the system from now on...really appreciate your advice...