'Return' system on plumbing

beer enigma

Just trying to get my head around this & wondered if someone could give me a simple explanation...

I currently have an oil fired central heating system.

Although the water in the tank heats when the central heating system is switched on, I cant 'just' heat the water. My plumber has told me that I'd need a 'returns' system which involves quite a bit of pipework to achieve this.

Anyone give me a laymans idea of what this involves ??

DublinWriter

I'm in the same boat myself, although my system is gas heated.

I have an A/B switch that supposedly lets me heat up either the tank or the rads.

No matter what the position, it heats both.

This is because the original builder cut corners with the plumbing. Instead of the rads and tank being on seperate circuits, they are on the one circuit.

My understanding of 'return' in plumbing parlance is that it's a complete closed circuit.

beer enigma

Yeah, that kinda makes sense....I'm just about to extend the house, so I wonder if its possible to include/disguise the new pipework during the build.

Cost of heating water at the moment is immense !!

crosstownk

I'm no plumber - but have seen different types of circuits. The best is dedicated flow and return for the HWC. The next is a seperate flow but common return - this can cause 'backflow'' when only one circuit is activated. The other type is simply one flow and one return and the coil in th HWC is just like another rad on the circuit.

How many pipes (not including the gas/oil feed pipe) come from your boiler?

stapeler

Is there a pump on/off button on your boiler? With the pump off, hot water should flow within the primary circuit (HWC). Pump on operates the the circuilating pump serving the rads. Boiler typically has water supply & return, both T'd off to HWC with circuilating pump on the return circuit.

JamesM

Andip wrote:

Just trying to get my head around this & wondered if someone could give me a simple explanation...

I currently have an oil fired central heating system.

Although the water in the tank heats when the central heating system is switched on, I cant 'just' heat the water. My plumber has told me that I'd need a 'returns' system which involves quite a bit of pipework to achieve this.

Anyone give me a laymans idea of what this involves ??

You can just turn off all the rads and then heat the water.

You will need extra pipework to be able to "automatically" switch off the radiator side of things.
It is possible that only the water and upstairs rads will heat if the waterpump is switched off. Then you only have to turn off the upstairs rads. Without the pump, it will probably take a bit longer for the water to heat.
Jim.

davidoco

Although it is possible on some systems (mostly soild fuel ones based on 1" pipework) to heat rads and water without the water pump -- do not turn off your water/circulating pump on an oil or gas system.

JamesM

davidoco wrote:

Although it is possible on some systems (mostly soild fuel ones based on 1" pipework) to heat rads and water without the water pump -- do not turn off your water/circulating pump on an oil or gas system.

There is no problem turning off the circulating pump on oil (and probably gas) systems, because the boiler temperature is controled by a thermostat.

Lex Luthor

Just go around and close all the inlet valves on each rad and you will only heat the cylinder.

GreeBo

Are you sure there isnt a motorised valve anywhere around the boiler?
Ours has one that turns on or off the flow to the rads...

DublinWriter

Lex Luthor wrote:

Just go around and close all the inlet valves on each rad and you will only heat the cylinder.

That's what I have to do, but it's hardly efficient as the pipes to the rads are getting heated also.

It's not a long term proposition with the price of gas going through the roof.

I'm preparing to get the replace re-plumbed with a seperate return circuit to the cylinder before Christmas.

ircoha

Paperback: see my answer here http://www.boards.ie/vbulletin/showthread.php?t=2054998611 of tonite

http://www.myson.ie/pages/motorisedvalves.htm

Reyman

You just have to bite the bullet and run an extra pipe from the boiler. You can common the return as already mentioned by Crosstownk.

Mine works this way and it's fine.

Forget about turning on and off the radiators every time -- that's a pain in neck and you'll have leaks and trouble from the valves in no time.

Also forget about turning off the pump -- you're not going to heat water through a coil on a gravity flow alone. And I don't like the safety aspect of relying on a thermostat alone to turn off the boiler

JamesM

Reyman wrote:

You just have to bite the bullet and run an extra pipe from the boiler. You can common the return as already mentioned by Crosstownk.

Mine works this way and it's fine.

Forget about turning on and off the radiators every time -- that's a pain in neck and you'll have leaks and trouble from the valves in no time.

Also forget about turning off the pump -- you're not going to heat water through a coil on a gravity flow alone. And I don't like the safety aspect of relying on a thermostat alone to turn off the boiler

There are an awful lot of "Don't"s and "Can't"s in this thread.
Andip said: "I cant 'just' heat the water" I told him how he could, without it costing him anything. Many people turn off their rads for the Summer and just heat their water. Not ideal, but it works. Some people just can't afford to install new systems. I did point out to him that he would "need extra pipework to be able to "automatically" switch off the radiator side of things."

Then someone said "do not turn off your water/circulating pump on an oil or gas system." There is no problem or danger with turning off the water pump.
Then we were told "Also forget about turning off the pump -- you're not going to heat water through a coil on a gravity flow alone." Many systems are set up this way and "IT WORKS"
Then we had "And I don't like the safety aspect of relying on a thermostat alone to turn off the boiler" What else turns off the boiler Also all modern boiler stats are dual stats.
It is great that people try to help each other BUT, I don't post about laying driveways or U-Values. People should stick to what they know about before making definite statements.

Jim

Reyman

JamesM wrote:

There are an awful lot of "Don't"s and "Can't"s in this thread.
Andip said: "I cant 'just' heat the water" I told him how he could, without it costing him anything. Many people turn off their rads for the Summer and just heat their water. Not ideal, but it works. Some people just can't afford to install new systems. I did point out to him that he would "need extra pipework to be able to "automatically" switch off the radiator side of things."

Then someone said "do not turn off your water/circulating pump on an oil or gas system." There is no problem or danger with turning off the water pump.
Then we were told "Also forget about turning off the pump -- you're not going to heat water through a coil on a gravity flow alone." Many systems are set up this way and "IT WORKS"
Then we had "And I don't like the safety aspect of relying on a thermostat alone to turn off the boiler" What else turns off the boiler Also all modern boiler stats are dual stats.
It is great that people try to help each other BUT, I don't post about laying driveways or U-Values. People should stick to what they know about before making definite statements.

Jim

You could be right in all this. Maybe we should ask the OP to turn off his pump and see how long it takes to heat the water via the coil. I'd be curious to hear.

JamesM

JamesM wrote:

It is possible that only the water and upstairs rads will heat if the waterpump is switched off. Then you only have to turn off the upstairs rads. Without the pump, it will probably take a bit longer for the water to heat.
Jim.

See my first post. The above is correct. I use the words "possible" and "probably".
I don't know the OP's layout, but I know that it is possible with many layouts, because I have seen it work.
What was your point about the thermostat ?
Jim.

beer enigma

JamesM wrote:

See my first post. The above is correct. I use the words "possible" and "probably".
I don't know the OP's layout, but I know that it is possible with many layouts, because I have seen it work.
What was your point about the thermostat ?
Jim.

Thanks for the advice - sorry for not coming back to this for a few days....

Its nice to hear a 'free' option James, thanks for that - I have 15 rads in the house, so its a pain to turn them all off everytime I want hot water, but it is something I do occasionally & its is WAY cheaper than the plumbing option, so much appreciated.

I think I'm going to have to go with the plumbing option though - my oil boiler needs replacing & I'm thinking of going for a gas boiler in its place - hopefully one of these that comes on when you reuqest hot water (name escapes me).

From a plumbing point of view, is it a massive job of piping ??

JamesM

Andip wrote:

I think I'm going to have to go with the plumbing option though - my oil boiler needs replacing & I'm thinking of going for a gas boiler in its place - hopefully one of these that comes on when you reuqest hot water (name escapes me).

From a plumbing point of view, is it a massive job of piping ??

The latest oil boilers are a lot more economical than older ones. Oil prices fluctuate and are down at the moment. Gas prices are increasing and will never drop.

Your plumbing costs will depend on your house and the layout of the existing pipes. For instance, if your boiler is outside, you may have to put the extra pipe(s) underground. Materials should not cost a lot. You can also bring an outside boiler closer or into the house. This will help economy.
Jim.