Example of installing a coil into a wood stove connected to existing radiators to share the heat to the rest of the home

Your coil makes good use to be able to put the logs inside.

Julian Elizondo, Navarra, has installed a coil embedded in the wood stove with all the necessary security . He says that he works very well considering the stove all day running, get temperatures of 20 ° C throughout the house without much cane put him into the fire, partly helped by the good insulation of the house as outside usually around them 5ºC half the winter. In total has cost about 700 euros between coil, copper tubes, electronic thermostat, valve autofill, another thermal shock, trap, etc, and to install have used the same gas boiler for move water ( as I explained in this post ) and have it plugged into the nearest radiator , eliminating it. Achieve heating elements 55 60 cm (aluminum radiators) and usually kept between 43 degrees and 50 degrees most of the day, Home on since morning.

Most of the installation is done it with the instructions of a cousin who is a plumber, who was the one who installed the auto-fill valve and electronic control of temperature in the boiler. Were turning and after several sketches decided the shape of the coil to better exploit its serious fire in C , as your stove is two doors and did not want to cancel any of the two doors.

The coil steel tube with 2 mm wall. or more will last a lifetime, because as a closed circuit oxygen from water by reacting rusting steel is consumed, until they oxidize more (formerly all radiators were much cast steel wall).

With the sketch and a template (made with some boards) was a blacksmith and charged him € 235 across the coil. Once in power, got down to work, marked with the coil placed where would the holes for installation and drilled using bits progressively smaller to larger, and then adjusted with a wheel and a drill:

Curve 1/2 "agenda item return water to the coil

Then he began with the installation of pipes ; in return he placed two junctions T-half inch;one for connecting the thermal discharge valve and one for the thermostat probe that operates the boiler pump connected in parallel with the boiler thermostat:

Diversions of return; the right to the safety valve connected to a drain

The thermostat is set to jump to 49ºC and 40ºC stop ; is likely to start warming is starting / stopping until they take the whole temperature circuit (not because it works by comparing temperatures input / output coil as in this example ), but this type of pump endure enough.

Note: It would have been better to put the valve on the outlet side of the coil, but I guess it has done so because it was easier to install on that side, and also fulfills its function to lower the temperature of the circuit, or because the water inlet is on the side of the coil back to the radiators.

In the picture below the discharge valve already in place, far right down to the drain:

The key is red tube drain circuit, if necessary once (in theory it should never be done, rather than for maintenance).

This flushed into the drain pipe (red key) and the thermal discharge safety

Both the circuit back as in back carrying a stopcock:

The tube that connects the valve low thermal and goes down the drain

He connected the coil to the radiator circuit through the nearest radiator ; the round is the upper and lower tube return; connected in either direction depends on how you performed the installation; usually affects only the order of heating radiators.

Julian has spliced ​​the coil to leveraging the same hot water boiler and heating circuit(has been discussed earlier in this blog here  and here ); is a very economical and practical solution (you can choose to heat with wood or gas or both at once); to connect the thermostat itself parallel to the boiler, you take advantage of all elements (expansion tank and engine) and gas is not consumed because it puts the minimum temperature regulator radiators.

I do not recommend open vessel systems , because although they are somewhat more secure against over-pressures, the disadvantages are greater; can damage the fill valve and having a flood, new oxygen is supplied to the installation continuously, it is more cumbersome, etc

On the other hand, has little problem that when using hot water boiler for the engine (to meet the demands of ACS, a higher priority than heating) and water stops flowing through the coil, but not serious thanks to thermal discharge system:

Set automatic trap and probe (top) connected to valve (below)

In the next picture from behind the brick wall where recessed stove is can be seen as you placed a tube from the top left of the pan to drill a hole in the right stove for the passage of the tube diameter Ø15 mm. to place trap and probe.

Top of the boiler: Exit the tube with automatic air vent and connection to the discharge probe

Julian told me they are very happy, although it has a little problem; when you want to give more cane fire, he heats the tube that goes to the probe much when exposed to heat (there does not circulate water and hot water tends to rise to the upper parts of the circuit) and he jumps valve ; think you can fix by putting a sheet that deflects heat pipe, or some insulation such as fiberglass.

Another solution would be to put the probe on another site , such as flow pipe with it close coil is more than enough to do its job is to detect excessive coil temperature rises, but it is important to give some solution because every time new water that gets into the circuit, oxygen will react oxidizing coil steel pipe installed is renewed.

This system does not need to put any other security system, because if you go light andexcessive coil temperature rises, the automatic filling valve installed in the boiler in the fill would get cold water maintaining the pressure of 1.5 bar .

In the worst cases, and in case of failure of the discharge valve, the coil having very little water, the danger of explosion by steam pressure is much limitedbesides that the safety valve be activated 3 bars of the boiler. In fact a coil is less dangerous than a hidroestufa approved, in case of problems with discharge sensor.

From here, thanks to Julian for sharing your experiment ; although I am not very keen on installing currently coils (for its performance compared to a hidroestufa of origin) is a solution thattakes advantage of a little heat from the recessed stove (improved from 10 to 40% return depending on the design of the coil).

Responsibility of the author:

This tutorial describes the installation of non-approved manner (not approved) of a heat utilization system.Are publicly available to share the knowledge gained, for home experiment; without adequate security measures can be dangerous for people. I am not responsible for what happens with evil or good use of this information; each must use their common sense and knowledge to safeguard their material and physical assets. 
Note that in case of a problem (fire, etc) with a system not approved any insurance will cover the damage.