Pro installed new Mr. Heater 2500btu radiant natural gas heater to Mr.Heater specs. when checked ceiling and the wall are hot 180 degrees is this normal or is something wrong or need heat shields?

SOURCE: turning on a radiant heater

whoo tall order! well, since that unit uses a piezo crystal spark gap that's half the battle. go to the grainger site and find a 24 volt electrically operated solenoid for gas use. anything else won't do. next go to the white rodges web site and find a spark igniter with a flame rod flame detector 24 volt. you'll also need at least a 500va 120/24 volt transformer. a standard honeywell stat will do. I'm thinking the unit uses a millivolt generator to keep the gas valve open. you could substitute a mercury button cell to energize the pilot valve and keep the valve open. give me your email addy and I'll see if I can draw up a diagram for you.

SOURCE: Natural Gas wall heater

It could be either the thermostat or thermocouple is not getting correct voltage so will intermittent turn on and off.

SOURCE: Need to heat water up more

I had same problem... fixed by turning hot water tank up to 145 degrees...but PLEASE do not do this if you have young children..that is hot and will burn!.. but does work(did this 8 years ago!)

SOURCE: Mr. Heater Natural Gas Garage Heater - 45,000 BTU.

my garage heater was working early this winter. I turned the thermostat to 0, but when I went to restart heater nothing happens, can you help me with this problem?

SOURCE: we have a 75,000 Natural Gas Mr.Heater

Make sure you are using the R and W terminals both at the heater as well as at the thermostat. Try jumping the wires together without the thermostat and see if the unit starts. If it does, bad thermostat. If you continue to get the error code, you may have a bad board.