Gravity heating

[aceman3]

Hi Guys,

After numerous years of thinking about putting in Radiators into my parents house I eventually got it completed.
The ehat source is off of a back boiler on a Stanley range. The hot water is by gravity. The pipe work is one inch from the back boiler to the copper cylinder. The copper cylinder sits in a hot press about six feed from the boiler and about 5 feet off of the ground.
The gravity hot water is functioning perfectly. buckets of hot water.

Is it possible to have convection heating upstairs? The reason I ask is that I thought we could and I don't. Basically I T'd off the hot water loop and put in a radiator loop. This run is about two feet higher than the heating loop and then runs horizontal for a metre. (this is where the heat stops) This I think is causing the issue but how could it? considering that all the pipe work for the upstairs radiators is horizontal. The radiator loops are 3/4" tapped off 1" gravity feed heating on the cylinder.

I have installed a Pump in the return loop for the downstairs radiators. Wired this up and turned it on and this circulated the hot water around to all the radiators upstairs and downstairs.

It will function with the pump but can I get it to function by convection?

Thanks for your help.
Aceman3

 

[Space cat]

First things first, is this an indirect cylinder with a heating coil?

Secondly, to get circulation you need a pressure difference which, in a gravity system, comes from the temperature difference between the vertical sections of the flow and return pipes. (The cooler water in the return pipe weighs slightly more than the hot water in the flow pipe.)

-- all the pipe work for the upstairs radiators is horizontal.

This suggests that your upstairs radiator feed and return are teed into the gravity loop at the same height, in which case you really don't have any pressure difference. To make it work you need to take the radiator return pipe downwards and tee into the gravity loop as low as you can - and it still won't be as good as a pumped system.

Incidentally, it's quite likely that, when you run your pump, it's pushing water the wrong way around the upstairs radiators and the cylinder heating coil - that's if you have a cylinder heating coil!

 

[DeltaT2]

Simply put; you need a big vertical column of Flow(hottest) pipe, to combat the resistance on the Return(coolest) pipe. Any circulated water will always take 'the path of least resistance'. So, in your case mate, it's going through the cylinder coil.

 

[aceman3]

Hi folks,

Thanks for that. Yes it is an Indirect copper cylinder. Might have to get a plumber in to have a look and advise further. Just thought I would ask here first.

Much appreciated for your help.

Aceman3

 

[aceman3]

Hi Guys,

Thanks for your help and advise. Have replaced the Horizontal run with a diagonal run and now have a gravity flow to the upstairs radiators.

Regards,
Aceman3.