No Hot Water after draining down system

[kevplumb]

may i add if your not sure don't try it

 

[flutterbye]

Thanks for all your help.

Finding the stat sensor in the boiler might well be a task too tough for me - especially without a technical manual.

Could it be fixed by draining down the system again, opening up the inlet/outlet pipes to the coil and flushing them with a hose?

 

[Softus]

Could it be fixed by draining down the system again, opening up the inlet/outlet pipes to the coil and flushing them with a hose?

Probably not.

 

[flutterbye]

Why not?

Or how about bypassing emersion stat so outer water boils?

 

[EliteHeat]

Or how about bypassing emersion stat so outer water boils?

Under no circumstances do this. It has nothing to do with your current problem and could give you a much bigger one.

Why not try loosening the top coil connection and trying to release some air as has already been suggested?

 

[flutterbye]

Is that the connection that is about half way up the cylinder, comes from the boiler directly and is hot? I've tried opening it but only get water - no trapped air.

 

[EliteHeat]

Is that the connection that is about half way up the cylinder, comes from the boiler directly and is hot? I've tried opening it but only get water - no trapped air.

Try the bottom one then, see if that works. These things normally work themselves out in time by the way.

 

[flutterbye]

If it might fix itself how long do you think I should wait before getting a plumber in?

I already tried (to no avail) the cold return feed from the cylinder.

Thanks for the help you've given me so far btw.

 

[EliteHeat]

If it might fix itself how long do you think I should wait before getting a plumber in?

I already tried (to no avail) the cold return feed from the cylinder.

Thanks for the help you've given me so far btw.

As you have an immersion heater anyway, your situation is not desperate. Leave it for a day or two with the hot water set to come on as normal (or even on permanently) and see what happens. You could also try sticking a hosepipe connected to the mains down the open vent in the loft and see if you can blow it out.

 

[MON5TER]

I've had a similar problem. On the pipe that supplies the coil, I have a T junction with a vertical pipe and an automatic air valve. Strange place to put one so I suspect it was installed to overcome historical problems.

I took the valve off and connected a hose to the pipe and forced cold mains through the system. I suppose there should be some sort of none return valve fitted to stop backflow but this did the trick for me.

Pushing a hose down the expansion pipe sounds like the same type of thing. I kept pushing water through until the F&E tank was filing from the supply pipe and the overflow discharged.

I am no plumber and this could be the wrong thing to do but it worked for me straight away.

 

[flutterbye]

Just to say thanks for all the advice on this. I solved it in the end by boiling the water as previously described.

 

[bab]

cool sorted scary but effective!

 

[Softus]

I solved it in the end by boiling the water as previously described.

Hm, that's not very specific. Which method did you use?

 

[flutterbye]

I used the technique described by Bab earlier in this thread by boiling the water in the coil.

You still haven't said why you think blasting some mains pressure water directly into the coil wouldn't have solved it?

 

[Softus]

I used the technique described by Bab earlier in this thread by boiling the water in the coil.

OK. Good. For one alarming moment I thought you'd tried the ill-advised immersion boiling trick.

You still haven't said why you think blasting some mains pressure water directly into the coil wouldn't have solved it?

Er, I didn't say that. It went like this:

Could it be fixed by draining down the system again, opening up the inlet/outlet pipes to the coil and flushing them with a hose?

Probably not.

...and my reason was that your plan was to add yet more air to the system and then flush out a blockage that didn't exist.