ravenheat 820/20

[unclefewst]

ok guys here goes again, with the long ongoing saga of my daughters boiler, symptoms of what was wrong, rads heating up when only hot water was selected what has been done so far, diverter valve changed, powered up, found out the pcb was faulty, changed, then thermocouple played up that was changed, pump changed , i hope you are all with me so far, there was suggestion that the system was fouled up with sludge, spoke to agile ''very helpful indeed '' i put in some sentinel x400 and ran that for about 3 to 4 weeks, central heating lovely, hot water still not right goes hot and cold intermittent this monday just gone, rapid drain down of system, (and under her sink/skirting there are two flexi tails coming off the 22mm flow and return i connected up mains water pressure to one outlet and the other by was of hose pipe with tap connector down the drain, i shut of flow and return on the 22 mm pipes to the combi and then hard flushed with mains water pressure each rad at a time, having 7 shut off and one open and going through them in turn, little muck came out, but nothing excessive as i could see, though it might have been suspended in the x400 solution, when this was done filled up and vented system opened up flow and return to boileer and flushed that through till clean (in fact seemed clean most of time ) have now filled up with ''ferroquest '' as most of you swear by it, have left this in for a few days and still in sytem will hard flush down again next monday and introuce x100 , however she states water still not working properly '' what on earth can it still be, it must be the cleanest internal system there is, any suggestions would be appreciated, this has been dragging on now for some time, but fortunately she has had central heating and has an electric shower and dishwasher so she has coped ok, but not the point, it should be working better than it is ps i have also checked the automatic air vent by ''atttaching flexi pipe to it '' when system was drained down and then refilling , and could hear the air coming out, kindest regards to you all especially agile regards dave

 

[Agile]

You have not treated the boiler as if it was a radiator!

There may still be dirt in the main heat exchanger. You might need to use DS40 and then seperately DS3 to clear that IF its the problem. Just in the boiler when isolated from the rads. Dont use too much at a time as it could make it leak! Try successive doses.

I would not have suggested the X800 after the X400 as they do the same thing.

Lastly there is the DHW heat exchanger coils. Just possibly they could be lime scaled and DS3 would be the solution but it must be circulated hot as it only works over 70°C. I thought Norfolk was relatively soft water but perhaps I am wrong. Lime scale is unusual in your boiler though.

Otherwise from my armchair I cannot suggest anything else for the moment. On site might be another matter!

Tony