One of the most revolutionary products to hit to camping product market in the last 10 years is the hot water system manufactured by the Coleman Company, called the Hot Water on Demand™.
Hundreds of thousands have been sold since its introduction with millions of hot showers being enjoyed by campers throughout the world. There are quite a few competitor products on the market and some are quite good, but not one is as easy to use as Coleman’s ‘HWOD’. The ‘secret’ of the HWOD is its’ ease of use. The term ‘plug & play’ is liberally used in today’s word of electronics but few products qualify more for this tag than Coleman’s Hot Water on Demand™.
To run it, all you have to do is screw in a propane gas canister, drop the pump in a bucket and turn the control knob. Five seconds later a hot stream of water comes out of the faucet.
Of course, to keep your HWOD in good shape, you have to give it a tiny bit of maintenance once in a while.
1. Keep the Battery Charged.
2. Keep the Hose Free of Kinks
3. Rinse the System Periodically
4. Maintain the Pump
5. Buy From a Retailer that Knows the Product
Keep the Battery Charged. One of the most simple maintenance tasks you can perform is charging the battery as frequently as possible. Since the HWOD uses a common 6 volt sealed lead acid battery you can charge the battery without having to completely discharge the unit. Most HWOD owners believe you have to ‘flatten’ the battery before you can recharge it. Nothing is further from the truth. The battery unit loves being charged, even after one minute of use. If the battery is left on a low charge (less than 6 volt) for an extended period, the battery unit will slowly deteriorate to a stage where the HWOD won’t run properly. If you’re in doubt about the state of your battery ask your camping gear store to test the battery.
Keep the Hose Free of Kinks. The hose must be kept free of kinks as a kink restricts or slows down the water flow. This causes the internal flow sensors to believe there is a lack of water supply, therefore shutting off the gas supply. Some owners think their HWOD unit is faulty when this occurs, however the flow sensors are designed to protect users from scalding hot water.
When you store your HWOD, remove the pump hose and hang it vertically so it can’t kink. Only wrap the hose around the base of the HWOD when you’re transporting the unit to your camp site or home. Don’t store it that way!
Rinse the System Periodically. As the HWOD does not have a constant flow of water running through it, calcium and scale deposits don’t take long to appear on the walls of the internal pipes. This is easily prevented by pumping CLR (calcium, lime, rust) cleaner through the system, a few times a year. Some HWOD owners claim that by running a vinegar solution through the system you will get similar results but this has not been proven. Afterwards pump clean water through the unit for 5 – 10 minutes to remove any residue. You can do this at a low temperature, or without the propane can installed but don’t recycle the waste water.
Maintain the Pump. The pump runs both plastic and metal parts. The metal parts can rust if left dry for a period of time. This in turn can cause the impeller to seize which will stop the water flow. The easiest way to prevent this is to remove the bladder adapter (the thing with the filter gauze built-in) from the pump with a wrench and spray a small amount of silicone spray into the pump.
Buy From a Retailer that Knows the Product. Every year lots of HWOD units end up as landfill, even though with a small amount of maintenance or simple repairs these units can give many more years of good service.
This is where a good retailer comes in. A retailer that knows the HWOD can help keep your unit in good shape and also repair the HWOD where the warranty period has run out. Good retailers do not only sell products, they should also be able to service and repair their product.

