# Gravity system for back boiler



## Brigid (26 Mar 2012)

Hi, 

I wish to get a back boiler installed but I have understood from my plumber that I will have to get a small circulating pump.  A couple of other people have told me that you don't need a circulating pump in if you install a gravity system.  I wonder if anyone can tell me how difficult a gravity system is to install and is it something that a plumber should know about or is it something that would have to be spec'd by an engineer?

Many thanks,

Brigid.


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## itsallwrong (27 Mar 2012)

Be careful of the back boiler area of plumbing.  It's a little bit of an art to do it right.
If you want lots of info on back boilers and stoves have a look at diynot.com which is a serious house site. In principal it is easy to put in.  You cannot have a pump on a single pass gravity system.  If the pump fails you have a bomb on your hands.  If you do get a plumber get someone who has a good few years under their belt.  Someone in there younger years will have no experience of old school heating systems like back boilers.
If your back boiler is a double pass - two circuits, one is gravity the other is pumped.  If its a single pass - only gravity.  Who is putting in the system?


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## Brigid (27 Mar 2012)

Thanks for this very good advice.  It is our plumber who will be installing the stove, he was recommended as being 'very good', but I think he will err on the side of caution, which is good rather than go and try to experiment with something like this.  I was going to get a double sided stove for the kitchen area and sitting room, but if the electricity goes I dont want to be left frozen as we cant use it as it has a electricity dependent pump, so we might just go with two separate stoves.  there is only one stove that I can find that is double sided and has a back boiler so I will print out the brochure and see if it is a double pass or single pass.


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## itsallwrong (27 Mar 2012)

Difference between a double door and single is fairly big. The single door has a boiler on three sides (back and two sides). Double door are just the sides.
Should be double pass. The heat off a stove is monter. 
If the stove is your only source of heating the house and water like mine is, then yes if the power goes you have limited use of the stove. 
You can have a fire but it must me small and then the gravity will deal with it.

Did you see the link I sent about stoves? You can see the options of installing one.

If you have a gas or oil boiler you would be in the same boat - even less means to get heat.
Look at the brand Hunter - they have double stoves and boilers


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