Cleaning a plate heat exchanger Worcester 40cdi

[Agile]

As far as we are told this is NOT a condensing boiler with an ali main HE.

In any case at the right concentration citric acid ( as contained with malic acid in DS40 ) is safe for a limited time at the right concentration.

Tony

 

[kinhell]

It's a Worcster 40 Cdi condensing boiler with an Aluminium heat exchanger. I rang Sentinel and checked with them if X800 was ok to use and they said yes.
I asked how long should I leave it in and they said its ok to leave in until the sludge clears and then drain, refill and add inhibitor.(contrary to what I have read about not leaving it more than 3 hours on here).
Thats what I have done and it seems to have made a difference. The water is still not piping hot as usual but useable now.
But then again when the water coming into the house is barely 5 degrees and is trying to rise to a useable temperature then I'd assume it'll struggle anyway. Just hoping with temperatures rising to 6 degrees outside at the weekend the incoming water temp will rise too and things will be back to normal.

 

[Happyplumber]

There is no way any manufacturer will agree with using an acid based cleanser on any aluminum heat exchanger ,wether its in there according to someone for five minutes or an hour.

Polymer based non acidic cleansers are freely available and will do the job properly and more importantly without causing any damage to the aluminium,thus making any claims on your warranty null and void


sentinel as well as fernox spends millions on creating a chemical to do a certain job which they have to test to stringent standards and then warranty it is fit for purpose.

There is no stipulation on any of the chemists who create these cleansers to be plumbers or boiler repair men

 

[Agile]

Which manufacturers are you speaking on behalf of ?

In spite of what you have said above, the instructions for Fernox DS40 ( citric acid based ) says:-

"""If aluminium components are fitted then DS40 System Cleaner should be circulated for no more than four hours."""

 

[Happyplumber]

Lets say worcester boiler even though I am not speaking on their behalf and the customer happens to have their boiler with an ali heat exchanger,lets see if you can ger written authoristaion from them that you can use an acid based cleanser in their heat exchanger

For sludge X800 , fernox F5 or any other polymer based cleanser is more then adequate It will take a little while longer then agressive acidic based cleanser but it will do the job very effectively without any having to worry that you have nuturalised all the acid properly afterwards or there is any residue left in the system

 

[Agile]

Citric acid is a very mild organic acid, just lemon juice! Certainly not aggressive like a mineral acid.

When I have a moment, I will ask Worcester by email as there would be a difference of opinion between Worcester and Fernox if that was true.

Tony

 

[Happyplumber]

please do tony,I for one would love to see you being right.I have always been lead to believe its no no.to the extent they even check the condition of the water for a warranty claim

If as you say they will agree to have their heat exchangers cleaned with acid i for one will be very very surprised

 

[Agile]

Most boiler problems are caused be a failure of installers to properly clean the system.

Those warrantee claims are usually refused by most manufacturers and their engineers visits usually become chargeable.

In the case of Worcester they seem to have a policy of being very nice to installers and it would not surprise me if they do not charge at least for the first unwarranted claim per installer.

Tony

 

[kinhell]

The X800 did the trick and the hot water is back to normal now. I've flushed it out and refilled plus added X100 inhibitor.

 

[nishnish]

The X800 did the trick and the hot water is back to normal now. I've flushed it out and refilled plus added X100 inhibitor.

Good news.

How long did you leave the X800 in for?

Sentinel don't seem to give a maximum time. As you've noted, there is quite a bit of erroneous information regarding this on this forum.

What period did you have to run the hot tap for and did you have to repeat this procedure much? Just until your hot water stayed hot, I guess?

I plan to do the same on an old 240 RSF system, in a house I've just bought, which seems to have been neglected. The DHW occasionally trips the overheat, but the CH never does.
I cold flushed the rads, in situ, yesterday and got out a lot of black crap. I plan to put x800 in today to clean as much of the remaining crap out. Also, fingers crossed, get the crap out of the DHWHE. I live in a 'very soft' water area (according to putting my postcode into United Utilities website, 1.9 Clarke units), so I think scale is unlikely.
I got 3L of x800 cheap, for a 16 rad 3 storey house.
Failing that I'll have to take off the HE to manually clean it. Yes, I have the time, but would prefer the easy route, if I need to do it anyway and it's been proven to work.

Cheers.

 

[poxy400]

take it out to clean it ,its easyer than it looks

 

[nishnish]

take it out to clean it ,its easyer than it looks

Thanks for the advice.
The x800 is pumping round now. I'll see how it goes.
Hopefully that will flush out the HE, like it did for the OP. Though I know it's best not to expect miracles from chemicals. I realise a manual flush would probably be more effective. Perhaps with some Kilrock K (formic acid) and a soft bottle brush. I'll do that outside with breathing mask, goggles, gloves, etc., as I did when pouring the x800 in, just to be safe.