Boiler Kettling And air in system

[mistrall]

I have recently had a y Plan conversion to my 70s installed heating system which also included a tank stat.
My boiler is a glow worm Hideaway which I am told is bullet proof and well worth keeping, Approx 10 yrs old.
Prior to the conversion from the gravity fed system I was not experiencing any kettling or problems with air in system. My plumber decided to move the pump from the boiler to the airing cupboard where all the other plumbing alterations took place.
Could the kettling be anything to do with trapped air in boiler?
Unfortunately my plumber is not being very helpful with this problem, he has been back after countless calls and fitted a valve which is supposed to automatically expel surplus air, doesn't seem to be working. any advice you can give would be welcome. Also how do I deal with an uncooperative plumber

 

[Breesey]

What are the relative positions of the pump, vent and cold feed pipes?

 

[mistrall]

What are the relative positions of the pump, vent and cold feed pipes?

I see he has tee connected the feed from heating header into vent I suspect this is where air is getting in. Hope this helps

 

[mistrall]

I see he has tee connected the feed from heating header into vent appros 4ft above floor level. The pump is at floor level

 

[Breesey]

Yes. The cold feed should be between the pump and the vent pipe, all after the boiler!

Get him back to do it properly!

 

[Breesey]

I see he has tee connected the feed from heating header into vent appros 4ft above floor level. The pump is at floor level

And then vent tee's into flow from boiler to pump?

 

[mistrall]

Thanks Breesey I will take another look (at work at moment) and attempt to get him back

 

[mistrall]

Are you suggesting this could be causing the kettling

 

[Breesey]

Are you suggesting this could be causing the kettling

Air in the system and kettling are not necassarily linked. You are likely to have air in the system because the arrangement of your system is not correct. The pump will very likely be drawing air in via the expansion pipe.

You could cause kettling if the pump is set at too slow a speed, so that the primary water lingers in the boiler too long and boils etc If your boiler is scaled up inside this could also cause kettling. Air in the sytem will not help a kettling problem but you won't get kettling just because you have air in the system, if you see what I mean!

Do you live in a hard water area? If so then your boiler is likely to be quite scaled up inside and this can cause kettling.

Also check the speed of your pump, turn it up if possible and see if the kettling stops. Trouble is that will probably draw more air in!

Where did the chap fit the auto air vent you mentioned? which sounds unnecassry! or do you mean a deaerator fitted between the cold feed and vent pipes?

As I say, you want the vent first after the boiler followed by the cold feed then the pump. Have the gravity feed 28mm primaries been removed and replaced with 22mm?