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, see this thread:

//www.diynot.com/diy/threads/air-trapped-in-boiler-circuit.415048/

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?

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.

 

[Agile]

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.

Were you dealing with sludge in the radiators?

Or lime scale in the boiler?

Regardless, you were not using the best chemical and not in the right place!

I am sure the boiler can be cleaned.

But that would not earn your plumber anything!

Tony

 

[cypher007]

just scale I would think, as the system heated up well once they connected the boiler correctly. plus when I first drained some water off, to add the x800, it wasn't that bad, just a bit grey/black no sludge.

I thought the x100 and x200 were supposed to be good, they have rave reviews. I didn't want to use something that was going to spring leaks everywhere, its a very old system in parts. one rad is over 40 years old.

 

[Agile]

Each has a specific application!

X200 is specifically for lime scale kettling. But it is needed in the boiler to do its job. But it is relatively mild.

DS3 is the strong acid for dissolving lime scale in boilers. It is very good but is not needed in radiators. It only works well when hot.

But all chemicals need to be used carefully and any acidic one can cause leaks on an old system.

Tony

 

[cypher007]

thanks for the quick reply. I did drain off a small amount after refilling the system just below the pump in the upstairs cupboard. then I poured in the x100 and x200, topped up, then ran just the HW circuit for a couple of hours before using the heating.

 

[cypher007]

original pipe work after they moved the pump and cocked up the flow/return:



unvented setup:


reworked boiler pipework so its the right way round:

 

[cypher007]

still kettling, but now its whistling.

 

[Agile]

The tun dish is not fitted in the correct position on the pipework, Should be within 500 mm of the T&P valve!

Tony

 

[James1991]

What tunes it playing? Sorry, couldn't resist.😃
I'd say the heat exchangers knackered.
Don't know if you'd get a replacement thou.

 

[cypher007]

could the heat exchanger have been knackered by running the system reversed for about 3 weeks, probably with about a third of the water being replaced with air every time the pump came on?

 

[cypher007]

The tun dish is not fitted in the correct position on the pipework, Should be within 500 mm of the T&P valve!

Tony

he probably wont some back to correct it. he'll just think im being an enormous pain in the ass.

 

[James1991]

Not sure what I'm looking at in the picture, but has he connected cold feed in to the flow before the tee for the open vent. It should be vent then cold feed before the pump. If it is, you need to get him back.
The HX could have been knackered by what you describe or it could be just it's age. It hard to prove either way.

 

[cypher007]

it would seem that the vent t's first then the cold feed from the header tank. the second t is behind the expansion vessel.

 

[Agile]

The tun dish position means that it does not meet the Building regulations!

Sounds like it has not had the benchmark certificate filled in nor the local BC notified?

Presumably he is not qualified under G3 to fit unvented cylinders! That is really a but naughty!

Tony

 

[cypher007]

I asked about the benchmark, after a plumber at work mentioned it, he came round filled out the sheet that came with the cylinder manual, said he would send it off to RM and I would get a guarantee cert through the post. ive now had the Gas Safe cert through for the unvented. god knows what he wrote on the form cause they obviously didn't check any temps flow rates.

is there any way I can find out if he notified BC?