Air lock to hot water tank

[Blue_Manc]

In the room directly above the boiler we have a hot water tank. The tank has a feed to and from the tank linking to the boiler. This feed goes through the coil and returns to the boiler.

On the feed side there is a venting point.

Continually I am finding (every 2-3 days) the water level drops (or air rises???) and i have to vent this point to allow for the water to heat up.



Is this a common problem - if so what are common causes/fixes?

Is there a "best practice" re venting - may I be causing the problem as I vent by not doing it correctly (eg Heating on/off, other venting points open/closed/ length of time to vent etc etc etc)

Cheers.

 

[StevenJames125]

has this problem just started or been there all the time?

so the boiler fires up for hot water but until you vent the air vent the cylinder doesn't heat up?

 

[Blue_Manc]

Seems to have been there for a while - although I would think it is more frequent - possibly since it was drained to fit a new rad - but may be my mind playing tricks and they may not be related.

The boiler fires up and heats water for a short while - then the rads heat up as none of the hot water is going to the coil.

 

[StevenJames125]

seems like you're getting air drawn in often - any union nuts not quite fully tight ??

 

[Blue_Manc]

Will go round and check - I take it I am just looking around joints/taps for any signs that they are not fully tightened? (Edit - I am keen - but lacking in any knowledge what so ever! )

 

[StevenJames125]

where is your vent pipe in relation to the pump?

have you got gravtiy hot water?

 

[StevenJames125]

Will go round and check - I take it I am just looking around joints/taps for any signs that they are not fully tightened? (Edit - I am keen - but lacking in any knowledge what so ever! )

the new rad check that and the pump unions - but see my other post above

 

[Blue_Manc]

Pump is belwo tank level - about 20 foot away in the bathroom (belwo floor) whilst feed for tanks is about chest high.

I assume it is gravity fed.

 

[StevenJames125]

gravity hot water systems are quite known to draw air in

where the air vent is that you keep venting, is it on the flow or return pipe form the hot tank? (top or lower pipe)?

 

[StevenJames125]

where the air vent is that you keep venting, is it on the flow or return pipe form the hot tank? (top or lower pipe)?[/quote]

 

[Blue_Manc]

The flow pipe (top one) ie the one that heats up.....

 

[StevenJames125]

The flow pipe (top one) ie the one that heats up.....

is the pump installed after the vent pipe or is there another feed pipe in between?

 

[Blue_Manc]

Not sure - how could I tell. The pump is directly above the boiler - the tanks is one room across - but no idea which way round it is set.

 

[StevenJames125]

could be drawing air in via the vent - and it's getting trapped there, at probably the highest level in your system

 

[Blue_Manc]

So is it just tighten the vent - or replace the vent?

Cheers for replies btw - much appreciated.