Mr heaterm Mhu 45

[heavylightweight]

I'm installing a Mr Heater Mhu 45......have spark and the fan comes on...however the flame will not ignite.......I'm currently using a barb-q tank..has anyone out there had any luck with this set-up or is this too little of pressure. Thanks and a big hello to you all.

 

[OhioSiouxFan]

I have just ordered a Mr. Heater 45,000 for natural gas. I presume you have the propane model. Here's a link to a review of the propane model, and the reviewer is using a 20# tank as well. So that must not be the problem, unless you have a low tank or something. Good luck!

http://www.northerntool.com/shop/tools/product_200316365_200316365

EDIT: This link is for the 75000 btu unit, but I presume if it works for the bigger heater it would as well for the smaller one; but I'm no expert.

 

[nehog]

Did you purge the gas line(s)? That may be your problem. You may also want to confirm there really is gas in the tank!

 

[curiousB]

Did you have a pressure regulator on the BBQ tank? I believe the propane heater assumes the pressure is already regulated down. If you hit the heater with full tank pressure you could damage the heater regulator. I have NG so can't say for sure but I'd be careful here...


..."A line pressure of 13” w.c. (330mm w.c.) should be maintained for liquefied petroleum (LP) gas."...

 

[dlewis]

Check you ac wiring if the polarity is backwards it will do that.

 

[heavylightweight]

Hi Peter....Bill the Cat rocks and the rest of the crew read the comic strip as it came out in the 80's.........But back to the issue at hand........no I have not ...today I hooked up a 100lb tank and same situation ..fan comes on it sparks but no ignition. How would I purge the system... Thanks

 

[heavylightweight]

hi again ....as far as the polarity goes...i read a few articles about the Big maxx...and it seams for trouble shooting.....I read to disconnect the thermostat and connect the R and W 18ga wires together....so is that what you are talking bout in regards to the ac wiring(dlewis).
As far as curiousB.....There was a regulator on the hose that I am using and it was for a LP heater as well. How would one check this ?

 

[toyotadriver]

I just installed mine. I thought mine was messed up at first but here's what I did to get it running. I did a test run with a 20 lb tank.

I first loosened the gas line where it enters the heater and kept it loose until some propane had vented out so I knew that the lines were full of propane.

Then, I connected everything and turned the thermostat on. It turned on and made some clicks but no flame. I noticed that I was getting a double flash on the LED. I turned the thermostat to off and let it sit until the fans shut off. I then turned the thermostat to call for heat again.

It took about 5 tries before the gas had made it through the lines and fired up. Works fine now.

Wire yours correctly and then turn on and off several times but when you turn it off, wait till all the fans shut off (few mins) and then turn it back on.

Your problem sounds just like mine.

 

[toyotadriver]

Also, a small propane tank has the same pressure as a large propane tank. What the small tank can't do is keep up with the withdrawal rate if you are trying to withdraw too much gas in too low of a temp.

A 20 lb tank can easily handle a 45k btu withdrawal rate unless it was to get EXTREMELY cold.

 

[heavylightweight]

Thanks I'll give it a go tommorrow ....can't wait to have heat with no fumes....and it's almost Friday beer nite too.

 

[dlewis]

hi again ....as far as the polarity goes...i read a few articles about the Big maxx...and it seams for trouble shooting.....I read to disconnect the thermostat and connect the R and W 18ga wires together....so is that what you are talking bout in regards to the ac wiring(dlewis).
As far as curiousB.....There was a regulator on the hose that I am using and it was for a LP heater as well. How would one check this ?

Not the thermostat wires the 110v power line.

 

[heavylightweight]

Fixed......It was the regulator...the on off of my little Readyheater was not a low pressure unit. It stared right up once I changed it over. Thanks for the help.