No hot water and struggling!

[Gargravarr]

OK guys, I need some assistance. Here is the system spec:

Baxi bermuda back boiler.

5 downstairs radiators

2 upstairs radiators

NO splitter circuit, Upstairs radiators get hot with just hot water on.

recently drained the system to fit new valves and add some pipework for new rads to be fitted later. (open pipework separated by isolation valves)

On initial refilling HW and rads worked well. next day no hot water at all.

Suspected airlock somewhere in pipes.

tried draining and refilling again.

Upstairs rads get warm and from what I can gather there is only one flow and one return pipe feeding upstairs for both rads and the tank, but still the pipe to the tank is cold... HELP!!!

 

[chrishutt]

NO splitter circuit

What's that?

We need to know if the hot water cylinder is heated by a separate gravity circuit or a branch circuit from a motorised valve (or 2 motorised valves).

Just to start you off, look at cylinder and see if there is an upstand pipe about 250mm long, rising from the cylinder connection about half way up. At the top of this upstand may be a manual vent point. Let the air out, and enjoy!

 

[Gargravarr]

Sorry, I am just an amateur at this

From what I can gather the tank and the upstairs radiators are gravity fed on the same circuit. the vent pipe is completely open. no valve at all. have tried backfilling the system and managed to get the flow pipe hot but still no heat on the return (which is odd to say the least). I think there is an airlock in the hot water tank itself but am not quite sure how to clear it. any other ideas would be greatly appreciated.

 

[chrishutt]

the tank and the upstairs radiators are gravity fed on the same circuit.

I'm afraid you need to do some research into heating system design - there's loads of stuff on the net. The radiator circuits are always pumped, and the circuit from boiler to cylinder may be pumped or gravity.

Do a search on this forum and you'll find pictures of pumps and motorized valves, then let us know what you have.

Am I right to assume you looked for the upstand pipe I mentioned and found nothing?

 

[Gargravarr]

Well, The upstand pipe is open ended right into the header tank leading me to belive that the hot water is gravity fed. the pipe to the hot water tank is the same pipe that feeds the upstairs radiators so these are also gravity fed I assume

However...

I have solved the problem. After draining the top floor I refilled it backwards using a hose fastened to the draincock. This managed to get heat into the flow pipe. The return was still cold but I turned the boiler to maximum and left it for about an hour or so. I then heard a bubbling through the return pipe and into the header tank which I assumed was the airlock being forced out of the tank pipework and up into the header so I reduced the boiler to the normal setting and waited for about half an hour. The return pipe was warm though not as hot as the flow (Well it wouldn't be would it ) checked again today and we have hot water.

YEHAAA!!! Now the wife will stop going on to me about not having hot water!!