Central heating system (banging noises )

[electech]

Hi can anybody help?
my central heating system has been making strange banging noises for a little while now and i'm not sure what it is. I have recently done a power flush through the system as i was advised that this would solve the problem, however it hasn't and the banging noise has started again.

I have noticed that when the banging occurs air bubbles come out of the pipe in the expansion tank which results in the water bubbling. I have noticed (i think thats what it is) that there is a dump valve connected on to the same pipe where the bubble occur, could that be fault?

Thanks,

 

[doitall]

Boiler make and model would be good.

The symptoms is poor circulation, so air or sludge in the boiler or the pumps not working.

 

[electech]

The boiler make and model is:
Baxi Solo 2 60pf

the pump in the airing cupboard is working ok because i tested it when i did the power flush before i put it back on. Are there any other pumps, perhaps in the boiler somewhere?

 

[D_Hailsham]

I have recently done a power flush

Was it a DIY power flush or did you pay someone to to it? If you paid someone, how long did they take?

Just noticed your reply just above, so presumably you did the job yourself. Ignore my questions

 

[electech]

Yes i did my own DIY power flush, i hired the equipment and brought the sluge remover liquid and inhibitor. I did about 6 to 8 hours flushing the system in both directions.

 

[bengasman]

Chances are the system is still full of crap. With all due respect, if a system is badly corroded, it takes more than sticking the pump on it for a few hours.
What chemicals did you use?

 

[bengasman]

Forgot to ask, how did you test the pump?

 

[electech]

I used a bottle of c/heating flusher cleanser to flush the system and then put some Inhibitor in afterwards.

Iv got a 0-300Vac Variac so i connected the pump to it and wound the voltage up.

If you think i need to flush it again what chemicals do you suggest i use?

 

[BingoBongo]

I used a bottle of c/heating flusher cleanser to flush the system and then put some Inhibitor in afterwards.

Iv got a 0-300Vac Variac so i connected the pump to it and wound the voltage up.

If you think i need to flush it again what chemicals do you suggest i use?

you should see if you can subbie for BG

 

[kevplumb]

View media item 14388

 

[JayJay1978]

Explain Kev, we're all learning............................................

 

[kevplumb]

explain what ???????

the fact that bg have enough clowns doing **** poor powerflushing at an exhorbitant price

 

[dextrous]

Gentlemen, the op is asking for advice on this DIY forum . At least he has tried powerflushing, instead of using BG for example. So, in fairness, do you not feel that it may be more appropriate to offer advice on how he may repeat the operation with a better result next time, instead of going off with your petty squabbles yet again

 

[bengasman]

For a badly corroded system, the least you need is a couple of bottles of x800, or better, a 5 litre can of FX2.
Apart from that, just sticking a pump on will improve things, but that is not how you powerflush.
If you have an open vent system, you start off with isolating the tank, and eliminating the bypass. Then you do rads one by one, and you measure to see if the rads are clean. You have to keep the water at the right temperature as well. Without the proper tools, you are going blind.
I would not recommend spending the time and money to hire the kit again.
Wait til the heating is needed again (soon enough sadly) and use Hyperflux from Kamco, or Fernox F3 that you can leave in 4 and 2 weeks respectively. May have to repeat 2 or 3 times

Still not sure how you tested the pump. You may have varied the speed, but how did you ascertain that the revs were correct and the torque sufficient?

 

[electech]

Q, Still not sure how you tested the pump. You may have varied the speed, but how did you ascertain that the revs were correct and the torque sufficient?

A, The Speed and Torque are pre-set on the pump. The operating voltage for the pump in 240v. Slowly wind the variac to the operating voltage, this will be the pumps correct speed. As for testing the torque, i put the pump under a small load by placing it in some water. The pump is only rated at about 2amps (not much load)

Thanks for the advice, will give it a try.