Bissell pro heat carpet cleaner?

The achilleas heel of the Bissell Proheat is the heater, it has a bad habit of becoming clogged up with detergent, take it to pieces and thoroughly clean it out including the input and exit valves, there are a lot of videos on YouTube showing you how to do this.
If you keep getting this problem, it maybe easier to bypass the heater altogether with a new piece of tubing.
Whilst your about it check the nozzles where the water ejects onto your carpet, these also become clogged up.

Delshan
August 2020

I have the 7901 model and the water can not flow if it has no place to get out. It has to either exit through the wand end or through the main nozzles. The only other options are through leaks in the lines. There is no return system that allows water to flow back to the main tank. How do you know the water is actually flowing? The usual problem with these machines (other than a belt problem) is clogging. This will not allow the water to exit the system. You should check flow out of the main nozzles and then out of the wand. These are 2 separate systems that branch off right after the pump. If the wand works but the main nozzles don't the issue is with the system after the pump as the line T's off to the wand and main system at that point. This can be the nozzles themselves, the heater core (in the handle), the trigger valve (in the handle), the flow indicator (spinner), or problems with the plastic tubing. Most of these issues will require you to remove the casing. You might surface clean the nozzles or try blowing air or water through the lines (access can be gained through the belt cover) or, if there is a small amount of flow still, by possibly flushing the system with clean, hot water. If these fail to resolve the issue you will probably have to remove the casing and clean out the clogs. There are many videos online that show how to do this.

Kim
January 2017