Pump/Boiler Problem

[Jerry1]

My Problem -

my boiler appears to be kettling.

Someone has suggested that the kettling has been caused by either poor circulation ie. pump problem, or by overtemp in the boiler pipes caused by faulty cut out on the boiler thermostat.

Have looked at the pump - it is quite hot compared to the temp of the pipes, the pump appears to be turning, and makes a normal humming sound suggesting normal operation.

Have looked at the thermostat on the boiler - when turned to the lowest setting it operates normally - boiler turns off so i dont think it is a faulty thermostat.

I am inclined to think that it is poor circulation.

can anyone shed any light on what might be causing the kettling, or how to check the efficiency of the pump

i have a stelrad ideal wlx boiler, fully pumped vented system, and the pump is a grundfoss. i have also just replaced the zone control valve and refilled the system with fresh water.

 

[ollski]

It's scale in the heat exchanger causing localized boiling spots, caused by age....turn the boiler stat down.

 

[Jerry1]

Thanks for that - have just turned the stat down. kettling is still present but just occurs over a shorter period now becuse stat cuts out earlier
Can the scaling be cleaned out? and if so what with.

What could be causing the pump to get hot? do you think this could be contributing to a poor circulation and hence kettling or is it purely down to the scale?

any thoughts?

thanks

 

[namsag]

Stick some sentinel x200 in system this will get rid of noise.

 

[Prof.plumb]

to be honest there is usually very little you can do. I would concur with the chap that said you should add some sentinel into the system. However, if the heat exchanger is blocked up there is very little you can do. You could try powerflushing but there are no guarantees.

 

[Jerry1]

Thanks for all suggestions.

Am a bit of a new comer to power flushing or putting sentinel into the system, is it just a case of putting it in the feed tank and running it thru the system and leaving it for a week or so?

Power flushing - what exactly is involved in this?

Help would be appreciated thanks.

 

[Prof.plumb]

That is the correct method of adding sentinel yes. powerflushing involves tapping a machine into the flow and return pipes. By taking either the pump out or a rad. It circulates water and chemicals around the system and dumps the rubbish to a drain. A good job should take 6 hours. In the finish the hope is that the machine will have removed as much scale and sludge as possible and the water running through the system is clear.

 

[Jerry1]

Thanks again, will look into both options.