Unused coil in hot water tank

[Saxony]

Hi, I am undertaking a renovation but need hot water before new boiler is fitted. I have a double immersion Gledhill tank with a fitted coil, which clearly I do not need at the moment. Can I blank off one end, fill it with water and connect the other end of the coil to a very small header tank - so it all heats up together? I am finding at the moment that so much heat is lost from this open coil. Thanks.

 

[Exedon]

I take it its the indirect coil your referring to?
As its not in use just cap it off or even just duct tape If your trying to stop the warm air.

 

[Saxony]

Thanks, yes it is the indirect coil. Surely if I cap it off at both ends it will expand/explode if the internal air heats up?

 

[snb1]

if its indirect just leave it un connected. ( it is purely an independant coil) if this is an unvented cylinder then you should be working on it as you need to have a current G3 qualification as it is deemed as dangerous as gas

 

[Justin Passing]

then you should be working on it as you need

---then you should NOT be working on it ---

You can cap it if you really want to. The air pressure would go from say 1 bar at 20° to 1 bar x (273 + 60) / (273+20) = 1.13 bar. Air compresses, it wouldn't explode. You can blow harder than that.
Personally if I were bothered by the airflow I'd use a bit of loo paper to bung the top end.

 

[Johntheo5]

And isn't that absolute pressure? So 0.13 bar gauge or less than 2 psig, not a lot, as stated above, if any worries, just bung one end.

 

[Saxony]

Thanks all. It is a vented cylinder.

 

[Justin Passing]

And isn't that absolute pressure? So 0.13 bar gauge or less than 2 psig, not a lot, as stated above, if any worries, just bung one end.

Yes, 13cm "head" of water, approx. I thought that was obvious but perhaps not. You'd have a bit more trouble blowing 1 bar .