Heater starts and runs but will not go to full force

If you have replaced the thermocoupler and it still wont stay lit then replace the gas valve.

Sounds like the button is bad. Try replacing it

Sounds like you have a bad gas hold on valve. I have a tip at http://www.fixya.com/support/r4258201-fix_gas_reddy_heaters_will_not_continue which explains the problem, how to fix it and where to get the parts. Let me know if you need more help.

Thanks for using FixYa and for the generous rating.

hardrocko

is the sensor for the thermocouple located in the right spot in the flame,remove it and if you have access to a propane torch,heat the end till its red hot and leave it connected to the gas valve,then start the unit and this will tell you if the sensor is properly positioned in the pilot flame on the unit itself,if not you could have a defective new thermocouple or another safety device keeping it from staying lit or the gas valve is faulty

if you get heat when it runs and then it shuts downs you need to clean your flame rod or replace the thermocouple if its a pilot lit furnace

I have the same problem with my Reddy heater 55-f. Is it thermal coupling or relay?

if its lit by a pilot your thermocouple is bad the purpose of the thermocouple it to keep the gas valve open

Try www.reddyparts.com for help

propane heater uses a hot surface ignitor. this operates off 120 volts and glows red/orange when actuated. it stays lit throughout the heater on operation.  on the backplate of the combustion chamber is a high limit with two wires coming off it.  these two wires connect to the spade connectors on the flame detector cappillary.  Once you establish a fire, the flame detector generates a 750 millivolt signal which is applied to the pilot/main valve assembly.  My diagram will show this. 

two items come into play here - 1) the hot surface cutout and 2) the flame detect Cd cell. Check alignment of the Cd cell or just replace it. The hot surface cutout has two terminals that plug into the two tabs on the millivolt generator.