Garage Underfloor heating.....need boiler.

[nel5on]

Hey guys,

When I made my garage floor, I installed 2 sets of wet UFH pipes. Now Its cold, and I need the floor to work....I have no power in the garage (run extension cord) and no gas currently. but my plan it to find a boiler or wood fire and run a Central Heating pump and a boiler or wood burner with a tank of water on it.

Any hints on a heating system? Diesel heater, paraffin heater, house boiler running on LPG.
I don't know how long it will take to heat the floor, but its insulated with 50mm of polystyrene, so will be faster than not insulated.

I guess Ebay is the best option to find the heating source.

Any hints from anybody on how to heat the floor water cheaply? 

[composimmonite]

What about a Webasto Thermotop C type heater off a Rover 75 diesel, Freelander, Disco, Galaxy and many other vehicles. They are used to provide a hot water system on boats so should do the job you require and run off red diesel with car battery.
Another option is an old central heating boiler and change jets to LPG and run off 47kg bottle. My house boiler just need power to operate the on-off heat solenoid so again a battery and small inverter should work.

[nel5on]

Thanks for the idea...Webasto's are not cheap. Can you change any boiler to run on LPG?

[composimmonite]

Nov 19, 2014 6:54:07 GMT nel5on said:

Thanks for the idea...Webasto's are not cheap. Can you change any boiler to run on LPG?

Webasto's can be bought cheap - I've had several and sub £100 every time. In fact one was brand new / unused and cost me £65. You need to find a firm who specialise in sorting out lease cars that have been filled with wrong fuel. The lease company pays to have the whole fuel system changed - including the Webasto. When you have something like a brand new Range Rover a few hundred for a Webasto is nothing to them.
AFAIK most boilers simply require jets changing to convert from natural gas to LPG. When we had a new cooker it included the jest and simple instructions to just swop the jets over so assume most boilers will be exactly the same. Check online for copies of the installation instructions. For example - www.glow-worm.co.uk/trade/literature/

[dodgerover]

Our kitchen floor takes about 2 hours to get upto temp but to be honest you really want to leave it turned on a couple of hours every day to keep the room temperature up, under floor isn't good for quick heating. You might be better fitting some rads for quick spot heat.

[composimmonite]

What about a homemade gas bottle heater with heat exchanger to provide hot water ? Site outside the garage and stoke up a while before you want to go into work.

[nel5on]

Thanks for the ideas, plan to do solar water heating when I can find some wet panels at the right price too.

[dodgerover]

I'm pretty sure the warm up time is going to be the issue with using UFH as a main heat source unless you are working in there all day? Solid fuel/ wood is going to need attention and planning ahead. A modern house boiler will need a power supply to run the fan even if you convert to LPG. Have you got a decent amount of insulation in the walls and roof as well as you will need to minimise heat loss as much as sensible/ possible - keeping in mind ventilation if you are driving vehicles in and out.
How thick is your screed as that will also have an impact on warm up (and cool down) time, the idea of a heated floor makes laying on your back underneath a car much more appealing though...

[froggy]

I put pipes in my floor when I built the garage but my combi pump wasn't man enough to push the water round as the two circuits were a bit on the large side so got a few double Rads and plumbed them in instead . Insulatiion is more important as I sacrificed a few inches to build it double skinned with an 80mm filled cavity and filled between the rafters with 100mm kingspan foam board so it stays warm

[bazzateer]

Don't even think about heating until you've insulated walls, ceiling and doors.