noisy boiler

[cliverm1954]

hi,
I have a fully pumped gravity fed heating system with thorn apollo 15/30B boiler, 6 radiators and a towel rad in the bathroom, I have a 3 port diverter valve, seimens rwb9 controller and indirect hot water tank. Ther problem is that the boiler gets very noisy when on high temp setting and the feed and expansion pipes get hot also the the overtemp trips and cuts the boiler out, when on low temp setting it is just a slightly niosy but bearable and does not trip out. I have tried flushing with sentinel x800 and then put sentinel x1oo in as an inhibitor but still noisy, can anyone point to a possible fault ??????????

 

[lightning]

Is the f/e tank pumping over when the boiler is running

 

[cliverm1954]

ater in f/e tank is warm but not sure if its because hot water has gone up and over expansion pipe or up feed pipe, feed pipe is hotter than expansion pipe ???

 

[cliverm1954]

have just checked f/e pipes, pipes have now cooled down, water is not going up expansion pipe and filling tank, pump overrun stat is working cos when boiler shuts down you can hear the pump still running and water is being pumped round system

 

[TheGasMan26]

Most likely your system is sludged up. Did you use X800 alone? you might have been better putting in X400 for 4 weeks first, also if the system is badly sludged its possible neither of these would clear it.

 

[cliverm1954]

hi, yes i used x800 but only left it in for the 4 hours the manufacturer recommended, should i use x800 again but leave in it for longer ????

 

[bengasman]

In the likely case of large amounts of magnetite, you need more than a run with x800. Either acid, or a bit of pipework replaced.

 

[Boilerman2]

It is not worth spending much money on an old apollo TBH
however if in good condition it may be worth getting a RGI to remove the heat exchanger and flushing it using DS40 acid whilst this is done a power flush of the whole system would not go amiss!

 

[cliverm1954]

hi guys
many thanks for the valuable info, am going to run independent tests on both heating and hot water systems oo see if I can evaluate where the problem could be and then take appropriate action from then

 

[Agile]

You dont describe the noise. Thats crucial to the diagnosis.

I am wondering if its kettling caused by lime scale on the heat exchanger for which you need to use x200 which can be left in the system.

If it were possible to isolate the boiler then HCl could be used at about 10% concentration.

Tony

 

[cliverm1954]

hi guys,
sorry the noise is like low drown, mostly on the high heat setting have set the balancing valve and hot water not going up f/e pipes am suspecting it could be scale in the heat exchanger slowing down the water flow as it seems to occur more when on call for heating rather than hot water, what is HCI ????
regards

 

[cliverm1954]

hi all you helpful guys, I am a vending service engineer and carry an acid descaling fluid, would it be OK to put this in the boiler via the pump feed pipe (it should go directly into the boiler without the need to dismantle it) and leave it there for about an hour then fill and flush the system

regards