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 .

 

[Phil]

Wow its a lot cheaper than my Numatic 'George' although it was my mums carpet cleaner before I nicked it!

 

[gaspastemania]

Well gave it the wet vac treatment today and can honestly say it was as much use as chocolate firegaurd !!!!

 

[armourer]

If its really being this much of a pain, would it be worth setting up a power flush machine and fill and drain at the same time.

I know its not ideal but it depends on how badly you want it done?

 

[gaspastemania]

To be honest going to put temp filling loop off the main supplying the f & e and link it into the supply and just blast it out from there . I have not priced for this as was dropped on me with not alot of time to survey system .

 

[quality]

To be honest going to put temp filling loop off the main supplying the f & e and link it into the supply and just blast it out from there . I have not priced for this as was dropped on me with not alot of time to survey system .

I had a similar problem recently and that exactly what I did to cure the air lock

 

[gaspastemania]

Do any of you guys class this as extra or put it in with youyr estimates?

 

[quality]

I consider it being part of the job but other may have different opinions

 

[SimonG]

Thats why I have a line on my estimate.

"The above price is an estimate only and not a final invoice."

So if things do go pear shape I have some room to manouvere, but I make cust aware at time its going to be more rather than springing it on them at the end.

I think you have a good case for charging the time you've put into it.

 

[WaterTight]

Thats why I have a line on my estimate.

"The above price is an estimate only and not a final invoice."

So if things do go pear shape I have some room to manouvere, but I make cust aware at time its going to be more rather than springing it on them at the end.

I wonder though - which would result in more jobs won and more money made...

a) including that caveat on your quotes - risking worrying customers with potentially escalating costs but making sure you're covered for every eventuality or b) upping the original quote price but stating that it is FIXED - covering yourself, most times, averaged out, if things become a bit more long-winded - and giving your customer a bit more peace of mind..

 

[WaterTight]

I reckon the answer is probably a) for big jobs and b) for small or medium ones.

 

[quality]

Purging and bleeding any system is down to experience and what your charge should reflect your experience.

I have had the odd domestic job that has taken possibly a day longer due these problems.

But on the other side of the coin I have commercial jobs (schools / hospitals) which have been completed 2 days before planned

If you chargibg a day rate all is ok but if your on price just make sure the price is a good one.

 

[Hybrid]

As SimonG mentioned earlier you could boil it. It's a last resort but if you pull the thermostat phial from the pocket on the heat exchanger it'll boil. Pop it back in after a short while and air lock all gone. Useful to have someone keeping an eye on the f&e.

 

[quality]

As SimonG mentioned earlier you could boil it. It's a last resort but if you pull the thermostat phial from the pocket on the heat exchanger it'll boil. Pop it back in after a short while and air lock all gone. Useful to have someone keeping an eye on the f&e.

It can boil and expand a good few times before you need to worry. The problem with large circuits like the current problem is that all the boiler will do is boil and expand straight to the tank and not disturbe any air.
I have spent hours sometimes 2 days issolating valves to reduce water volume hence increase flow to rid large systems of air.
Believe me there is no quick way out, cold water main can do a lot of work for you when your in these type of holes

 

[Phil]

Sorry the wetvac didn't work I feel a pratt now, did you suck plenty of water through and was the water water heated (warm up heating and turn it off), you can normally feel the pipe getting hot after you've pulled water through, then turn the valve off and connect back up. This is a big system though so maybe it will take longer.

The wetvac will come in handy though, I used mine all day today while fitting a shower pump, undoing flexi's of old pump with water seeping out etc.

 

[gaspastemania]

I have spent about 2 hours messing with it with no joy, can hear the air moving around and occasional bubble coming out of tank . In this scenario i think its size of systems and lenghths of pipe runs . A small domestic set up and reckon wet vac no probs. Im not into boiling them up as done it once and not again as boiler went kaput . It dont help either as cant find a plumber to help who has half a brain .

 

[Gray0689]

Close off all rads that are heating and connect mains to the vent and blow it out