Make sure that that the heater is plugged in. The cord could have been jostled while cleaning or otherwise pulled loose. If the heater cord is firmly plugged in, it is good idea to test the outlet.

An easy way to test whether the outlet has power is to plug a lamp or other device into the outlet. If the device works, the outlet is obviously not the problem. If the outlet does not have power, the circuit breaker may have tripped off or the fuse is blown. You can check this yourself or have it checked by a qualified electrician. Either way, these steps take far less effort than replacing the heater.

If the outlet is functioning, chances are the heater has failed and you will need to purchase a new one. The basic design of heaters has not changed much over the years. The same can be said for how the heater is installed. Waterbed heating system components included the heater pad, temperature sensor, thermostatic control unit, power cord and control cable.

There are many good quality heaters available, either at your local waterbed supplier or online. Never buy a used heating system for your waterbed and make sure the heater you buy is in the factory packaging. Since you will need to drain and refill the mattress, remember to buy a sufficient quantity of conditioning chemical.

Regardless of where you purchase the heater, never buy a waterbed heater that has not been approved by a recognized testing organization. Two highly respected organizations are Underwriters Laboratories and the Canadian Standards Association. Products approved by these organizations are prominently labeled with the testing organizations logo.

Replacing the heater involves several steps, starting with unplugging the old heater. Next, you will need to drain the water from the mattress. I find it much easier and faster to use a pump than to try to siphon the water out. Small pumps can be found at many equipment rental centers, home improvement stores or a local waterbed retailer.

With the mattress empty, it a good time to thoroughly clean it. Give the mattress a good flushing and wipe down the outside with mild soap and water. Thoroughly inspect the mattress for signs of wear, especially areas where the vinyl is becoming brittle or stiff. This condition may be particularly evident where the heating element was placed. If the vinyl is stiff or brittle, you will need to buy a replacement mattress.

Next, clean the safety liner, again using mild soap and water. Pay special attention to the area where the liner contacts the heater pad. Replace the liner if the vinyl has become stiff or brittle. Remove the old heater components and dispose of them properly. With the mattress and liner removed, it is also a good idea to inspect the frame structure.

Remove the heater components from the packaging, look for the UL or CSA logo and inspect the components for any obvious damage. Find the manufacturers instruction guide and read it thoroughly. Take the heating pad and place it in the center of the deck, making sure it is at least twelve inches from the frame rails. The temperature sensor should be placed at least six inches from the heater pad.

Route the power and control around the outer edge of the frame rails and towards the head of the bed and through the bottom of the decking. Do not plug in the heater yet. Replace the liner making sure there are no wrinkles over the heating pad. Replace the mattress again removing any wrinkles on the bottom, especially over the heating pad.

Add the proper amount of conditioning chemical and begin filling the mattress with water. Once the mattress has been filled with at least six inches of water you can plug in the heater and set it to the desired temperature. Finish filling the mattress and remove any excess air.

Remember that it can take as long as three days for the water to reach the desired temperature so patience is the rule here. Use a thick piece of foam or a comforter an insulating pad until the water is warm enough.