running the coleman hotwater on demand
off the camper watertank

Modifying our Coleman Hotwater On Demand unit to run off our camper trailers water tank and pump has worked out to be one of the best things I have done to our camper. This gives us the ability to have quick access to hot water without having to worry about the water supply. Additionally the hot water system can be easily unplugged and relocated for use as a shower using its own water pump and external water supply.

To achieve this I used the following parts-
- Hotwater on Demand hose adaptor
- 2 metres 11/16th reinforced plastic hose
- 2 meres 3mm twin core wire
- plastic “T” connector
- inline water tap
- hose clamps
- snap on hose fitting
- rubber “O” ring grommet (optional)

The first step was to extend the water hose and control wire on the Coleman water hose adaptor. To do this I simply cut the control wire and soldered in approx 1.5 metres of 3mm twin core wire extending it to approx 1.5 meters in length.

To extend the water hose I unscrewed and removed the existing fittings and original short hose from the adaptor. I replaced this clear hose with approx 1.5 metres of reinforced hose (the reinforced hose is less prone to kinking). As the diameter of the hose was slightly larger I used a round file to enlarge the hole in the securing gland nut on the fittings.

Prior to fitting the end to the hose, I measured the hose against the wire to get them at the same length and the taped the two together to create a loom.

Next job was to fit the “T” piece into the output of my existing water pump. Then add a small amount of hose and clamps to connect the inline water tap then another short length of hose and clamps to connect to the snap on hose fitting that will attach to the Hotwater on Demand hose adaptor.

Drill a one inch hole in the kitchen box fitted with a rubber “O” ring grommet. Then join it all together and secure the hose adaptor into the kitchen box.

I used the snap on hose fitting to keep the hose adaptor unit standard, as it can be very easily removed and refitted if you want to use it in another application or from an external water source

february 2012