ideal classic RS250 kettling

[cypher007]

ok had a new unvented tank fitted and system changed from gravity to fully pumped.

initially the plumber connected to the original gravity connections on the boiler and got the flow and return the wrong way resulting in trapped air, probably in the heat exchanger.

anyway that's been sorted, they connected to the fully pumped flow and return connections that they capped off originally and I don't have the trickling bubbling noises. what I do have is kettling still.

so ive tried x800 for about 18 hours, put it through each rad one at a time with the pump on high then left it standing in the system overnight. put heating on for 1 hour in the morning emptied refilled run for another hour, emptied refilled. then I added x100 and x200.

to be honest looking at the water coming out I don't think its a sludge issue, plus my rads get toasty now the boiler is flowing the right way round. what im thinking is maybe because the boiler probably didn't have a full heat eachanger for about 3 weeks its scaled up really bad. if im patient do you guys think the x200 will do its thing? should I put another tub in, as ive actually got 12 rads, but some are tiny and only 1 is a tall double and 2 are short?

im wondering about draining down and adding the x200 directly to the heat exchanger or would vinegar work better?

p.s. the plumber recons its knackered and needs replacing, hmm

really. must want to quote me for a nice new boiler after doing such a good job on the unvented.

 

[diamondgas]

Do you live in a hard water area? If not then scale it most likely not the issue. Does the 'kettling' start early on when heating up or later when hot? how long has it been kettling for?

To be honest you could be fighting a loosing battle if the issue is 'sediment' build up IMHO

 

[cypher007]

Do you live in a hard water area? If not then scale it most likely not the issue. Does the 'kettling' start early on when heating up or later when hot? how long has it been kettling for?

To be honest you could be fighting a loosing battle if the issue is 'sediment' build up IMHO

last night I did a bit of a test:

the flow pipe is slightly warm, im guessing due to it having a pilot light. anyway from a cold start the boiler starts to kettle after about 30-60 seconds. yet the flow pipe is barely any warmer. this is with the pump on setting 3. ideas? flow prob or water trapped behind lime scale?

the system doesnt take ever so long to start heating up the rads.

p.s. its a hard water area 336ppm.

 

[diamondgas]

Are you in a hard water area? If it starts almost immediately then you have either lime scale or iron 'flake' sediment on the inside of the heatexchanger, at a guess?

Des the system take a long time to heat up, is that what you're saying last sentence?

 

[cypher007]

no i wouldnt have said it takes a long time maybe a few mins longer than our old house, but that had a condensing boiler that was rated for more than was needed.

 

[diamondgas]

Hard water area? Lime scale on the end of your hot taps? kettle furing up?

 

[cypher007]

Hard water area? Lime scale on the end of your hot taps? kettle furing up?

yeah and then some . the taps look like there growing stalactites. im fitting a softener probably this weekend, as ive given up on getting anyone local to fit it or even fit it properly.

 

[diamondgas]

yeah and then some . the taps look like there growing stalactites. im fitting a softener probably this weekend, as ive given up on getting anyone local to fit it or even fit it properly.

:rofl: well serious lime isn't something I've had to deal with my neck of the woods. it'd depend on the severity of the build up as to how successful chemicals will be. Doesn't it take a while for x200 to take effect though?

 

[cypher007]

the x200 has been in about a week and its still whistling knocking.

 

[diamondgas]

the x200 has been in about a week and its still whistling knocking.

Sounds like quite a build up! Maybe someone with experience of scale will be along who can better advise

 

[stevetheplumber]

i would use some x 400

 

[Aquazone]

To be fair I've had very little success descaling or getting baked on sludge out of cast iron heat exchangers on Suprimas/profiles/classics.

Never er seems to give good results and usually ends up leaking. Even putting powerflush round it hasn't helped.

In the past I have tried x800 F5 F3 x400 ds40. Usually makes it better but doesn't cure it.

 

[cypher007]

i would use some x 400

what pour into heat exchanger and soak then flush or put in system?

 

[cypher007]

anyone?

 

[newcastle phill]

Its not an exact science.
As has already been said.
I did one once which was so old and knackered it just went PING after a week.
And horrible black mess all over.

 

[cypher007]

Its not an exact science.
As has already been said.
I did one once which was so old and knackered it just went PING after a week.
And horrible black mess all over.

wow what did it do? pop a seal on the heat exchanger plugs?

 

[diamondgas]

http://pu.edu.pk/images/journal/jfe...Experimental Study Chemical Descale (2) f.pdf Any use to you?

 

[cypher007]

http://pu.edu.pk/images/journal/jfe...Experimental Study Chemical Descale (2) f.pdf Any use to you?

thats some scary ****. think ill stick to vinegar or x200.

 

[newcastle phill]

wow what did it do? pop a seal on the heat exchanger plugs?

No not pop a seal.
Internal corrosion where over many years of sludging up, poor maintenance and mildly acidic water simply eats away at the iron. The walls become thinner through this process until finally they become so thin through corrosion the weakest point goes and the water leaks out

The cleaning agent just rapidly accelerates the weak spot and makes it apparent

 

[cypher007]

ok filled the heat exchanger with white vinegar for about 3-4 hours. then drained via the plug in the heat exchanger. result is same kettling.

some interesting observations though:

after turning on the boiler with the pump on full, after a minute or two the kettling started. so I touched the flow, just warm, touched the top third of the heat exchanger just warm, touched the bottom 10% of the heat exchanger, arrgh!!! bloody hot.

does this indicate a flow issue or boiler setup issue?

p.s. it took quite a while to get the heat upto the top of the heat exchanger.

 

[PETE 123]

Flow and return reversed

 

[cypher007]

it did have that problem after the plumber fitted the unvented, but I figured it out and got him back to fix it. trouble is im not sure if that has caused a some irreversible damage to the heat exchanger.

 

[Millsy 82]

Are you gsr? Why are you removing the casing to get to the heat exchanger? Get someone in who is gsr to look/ sort it for you.

It does sound to me as though it is piped up back to front still which will be the cause of your problem.

 

[cypher007]

defo piped the right way round now. I would get a gsr to sort it only the unvented gsr g3 man and crew were the ones who piped it the wrong way round in the first place. I bitched about the boiler sounding like it had someone pouring water into it, and was told your boilers 15 years old and knackered, yes well reverse flowing it doesn't help.

so now I have a distinct distrust of some gsr's. not to mention trying to get them to turn up is an art form all of its own.

 

[Dotty]

And we have an inherent mistrust of diy Dave and his attempts to repair his boiler himself.

Thread closed.