Descaling a Glow worm Heat exchanger

[Porker]

Having put up with a noisy heating system for most of the winter so far, I have finally concluded that the problem is a scaled up Heat exchanger on my Glow worm Ultimate 120FF. There is currently some X800 (Ferroquest) circulating. I have two questions - How long can I leave this in the system? - it has quietened down quite a bit after 1 hour but I would rather give it a little longer as I did this a couple of months ago (3 hours) and after refilling was about the same as before. The info on the bottle does not really say, just a limit for aluminium (there is no aluminium in my system).

Secondly, if this does not cure my problem, is there an economical way of getting it descaled using any other method i.e. replacing or removing and cleaning? The boiler was installed some time in 1997 and IMO should last a little longer. The scaling, I think has been caused by a long term leak (now fixed) that has been letting fresh water in over time into the F&E tank. We are talking around £1600 just for the boiler plus installation. If there was something I could do for say £500 maybe worth it.

 

[Fluffster]

If your heat exchanger is the prob a replacment should be more viable than a new boiler.
The aluminium mentioned on the x800 container relates to aluminum heat exhangers as it eats them up compared to a stainless steel h/e.
I am not sure if your model has one you can always check on the Kamco website.
A powerflush can clean your exhanger and whole system for about £370.
Pete

 

[ChrisR]

Ferroquest is OK for a couple of days I believe as it's not acidic. I've left it that long a couple of times.
Do tell us how well it works!

 

[Agile]

X800 is a non acidic chellating chemical primarily for dealing with metal oxide sludge in the system and is not the best treatment for your problem.

The leak will have caused metal oxides so its use will not have been wasted. Drain and refill the system or dynamically flush it.

If as you seem to say the problem is kettling in the boiler then that needs sulphamic acid just in the boiler and at about 70 °C for a couple of hours perhaps repeated twice.

Close all rad valves and introduce the Sulphamic into the boiler and force it to run on hot water by turning up the cylinder stat. The drain and repeat, finally flushing the system well before adding X100 inhibitor.

Tony

 

[Fluffster]

Good advice Tony.
Pete

 

[Porker]

Thanks for the advice guys. I've run the X800 for a couple of days and the system is now pretty quiet. It's done this before though. I've drained the system and will refill in a couple of days (I'm away for a few days on business). I fully expect the banging to return on refilling but...

Agile - I've taken on board your advice and will do as you say with the acid through the boiler. There is a chance I can borrow a Kamco flusher that will take acid. Would this be easier/ better than pumping round HW circuit as I believe you can connect straight onto boiler?

Will let you know what happens.

If worst comes to worst and I need to replace the boiler, what would you recommend with a capacity of around 120,000Btu? The existing Glowworm Ultimate 120FF would be a great replacement but they are expensive and it is questionable whether I come under the exemptions for a non-condensing option. (I'm venting just under 2.5m from neighbouring house).