air lock

[gaspastemania]

Need idea of removing airlocks on large gravity circuit, Has 1 f & e tank which feeds 3 zones of heating which has a boiler for each zone.Approx 20 radiators over the 3 zones with only a couple in each zone warming up . The circuit itself is alarge circuit and is old . Hestitant to back fill because of age of the circuit and was not able to use bungs either due to cust wanting full drain down .
The AAV'S by the boilers are chocked up but dont want to go down the route yet of removing them if i can avoid it so any suggestions of getting the air out through vents would be appreciated .

 

[WaterTight]

I'm inexperienced and shouldn't really be offering someone like you advice and I'm sure by idea is moronic...but could you back fill it using some sort of pressure reducing valve turned down as low as you can to back fill with as little pressure as possible...?

 

[ecowarm]

Is it air or could it be sludged up?

 

[SafeGasInstall]

you know very well that options you have a limited to mains push in ,if you try the standard close the ones that work and
have pumps on 3 , what I did on one job was had all air vents on rads open down stairs and start filling and had the pump going like 1-2min after and soon as I had a full rad i did turn them valves off and moved to next one ! it was a fully pump ch and gravity water on a back boiler and pump wast boxed in I could not even get to it to (on the side of a unit with i think 4 book shelf's full of books )

 

[SafeGasInstall]

i think it could be what ecoworm mention above !

 

[gaspastemania]

Really trying to avoid any back fill scenario in all honesty but as a last resort then may have to .

 

[SafeGasInstall]

one thing mate ,did it work before hand ?

 

[Phil]

20 rads? 3 boilers, where are you working Buckingham palace. :dead:

I've always found the best way is to remove each cold rad at a time and put the old wet vac on the rad valves, soon pulls out the air.

 

[gaspastemania]

Sludge is a possibility as air vents are leaking and looks like they are sludged due to water the weeps on them look like thick brown gunk , however on drain down water was standard grey and not overly gloopy. When i filled back up had two guys doing the venting whilst i was up by tank ,i can hear the air clanging around system but it isnt finding a spot to ping out the vent .

 

[Phil]

Actually thinking about it, is this microbore?

 

[kimbo]

If youve tried putting the pump on no 3 etc dont forget to close the by pass fully.

 

[SimonG]

I like to boil it, really shifts the air, but that's on the oil boilers.

 

[gaspastemania]

one thing mate ,did it work before hand ?

Was working on different part of the building at the time on a different circuit and builder was urgently requiring a sudden extra rad move in another part of building where the 3 boilers are so never even got chance to flash them up .

 

[SafeGasInstall]

20 rads? 3 boilers, where are you working Buckingham palace. :dead:

I've always found the best way is to remove each cold rad at a time and put the old wet vac on the rad valves, soon pulls out the air.

like Phil's idea never thought of it

 

[SafeGasInstall]

must be a big old place

 

[gaspastemania]

Its a large building to say least and circuit has long runs and goes all over the place . The whole building itself has 5 different circuits inside. Theres no microbore in sight all 28,22 and 15 mm had left the pumps on the 3rd speed all night and alot of air had shifted out the vent but still has alot inside it. Kinda picture 5 town houses all interconnected gives you idea of size.
Isnt that a bit dodgy with wet vac ??How do you go about that??
Have used a dog grooming blower before and that works a treat but shoves hell of alot of pressure into circuit .

 

[Phil]

I always try to avoid full draindowns if I can, they always lead to stressful late finishes although sometimes you have no choice - especially if customer prefers it??

With the wet van you can simply snatch new aav's on, as long as the original pipes are 15mm and you have everything to hand!

 

[Phil]

Its a large building to say least and circuit has long runs and goes all over the place . The whole building itself has 5 different circuits inside. Theres no microbore in sight all 28,22 and 15 mm had left the pumps on the 3rd speed all night and alot of air had shifted out the vent but still has alot inside it. Kinda picture 5 town houses all interconnected gives you idea of size.
Isnt that a bit dodgy with wet vac ??How do you go about that??
Have used a dog grooming blower before and that works a treat but shoves hell of alot of pressure into circuit .

Sometimes just cracking open the union and using wetvac to catch the water will work as it gives an 'open door' for the water to flow free and sputter out the air.

 

[gaspastemania]

This wasnt actually priced into job originally was a sudden out of the blue extra where as usual no time to price or look at anything as builder was motoring ahead.
When you said lift rads off , do yopu mean stick wet vac over rad valve ,open rad valve then on with wet vac??

 

[SimonG]

Gonna have to invest in a wet vac, seems a very versatile tool.

 

[ecowarm]

Need idea of removing airlocks on large gravity circuit, Has 1 f & e tank which feeds 3 zones of heating which has a boiler for each zone.Approx 20 radiators over the 3 zones with only a couple in each zone warming up . The circuit itself is alarge circuit and is old . Hestitant to back fill because of age of the circuit and was not able to use bungs either due to cust wanting full drain down .
The AAV'S by the boilers are chocked up but dont want to go down the route yet of removing them if i can avoid it so any suggestions of getting the air out through vents would be appreciated .

Its a large building to say least and circuit has long runs and goes all over the place . The whole building itself has 5 different circuits inside. Theres no microbore in sight all 28,22 and 15 mm had left the pumps on the 3rd speed all night and alot of air had shifted out the vent but still has alot inside it. Kinda picture 5 town houses all interconnected gives you idea of size.
Isnt that a bit dodgy with wet vac ??How do you go about that??
Have used a dog grooming blower before and that works a treat but shoves hell of alot of pressure into circuit .

Is it pumped or gravity? I would think there is good chance of it being blocked with sludge

 

[gaspastemania]

gravity fed .

 

[Phil]

This wasnt actually priced into job originally was a sudden out of the blue extra where as usual no time to price or look at anything as builder was motoring ahead.
When you said lift rads off , do yopu mean stick wet vac over rad valve ,open rad valve then on with wet vac??

Yes thats about the size of it, it would be even easier if there was a drain off valve fitted. I would have suggested caution if there was microbore involved (sucking dirt into manifolds etc) but if its 28-22-15 then I would go for it.

If I had all my tools stolen then the wetvac would be one of the first things I'd buy, I think its a must have rather than a luxury tool.

Great for when the hot taps are airlocked as well as you just seal it round the tap with your hand and it restores the flow more or less straight away. Make sure the open vent isn't blocked or the cylinder with start thundering as it tries to implode.
:29:

 

[gaspastemania]

Have heard of using wet vac before but never thought it would have enough suck to pull out airlocks , looks like a trip to wickes then this week ,,,thanks.

 

[SafeGasInstall]

do not go to wickes for this get one of this will not regret my recommendation
Sealey PC200SD Vacuum Cleaner Industrial Wet & Dry 20ltr 1250W/240V Stainless Bin (PC-200-SD) have exactly the same one