Mr Heater Install HELP!

[400excracer]

OK, so I installed my Mr Heater MHU45 today and after everything was finished I turned on the gas and cranked up the thermostat and nothing. All I got was a flashing green light. I am still not sure about the thermostat wiring. I put both the black and red wire to the C terminal on the block. Also, I didnt hook up the ground from my main power cord since I didnt see a place to wire it to and it didnt say anything about it in the directions. I searched this site for similar issues but I couldnt find anything. I would love to fix this myself without calling a professional. Any suggestions??? Thanks

 

[Red Green]

I just happpen to have intalled my MHU45LP today. Was the light flashing slow? On the back panel there is a screw that doesn't have anything hooked too it by where the gas line goes in that is your ground screw.

 

[Red Green]

There are Two wires for the thermostat and they hould be wired to a "R" and a "W" on the block.

 

[400excracer]

I hooked up the red wire to R and the white wire to W and I still have nothing. The green light that is flashing is blinking about once every second. I am not sure if this is fast or slow since I have not seen the other.

 

[Red Green]

Thats slow. There is a "switch" by where the gas line hooks in did you turn that to the on postion? Are the wires hooked the same R and W on your thermostat? Also is the thermostat moved so that its calling for heat?

I know some of this stuff is simple but it still needs to be checked.

 

[Red Green]

http://www.garagejournal.com/forum/search.php?searchid=872366&pp=25
Lots more info. I will check back tomorrow and see if you got it going.

 

[400excracer]

I checked the switch and it was on. I wont have a chance to double check the wiring on the themostat until I get home from work tonight. Thanks for your help.

 

[400excracer]

I found an extra minute or two this morning to check my conections at the thermostat and they are correct. I am going to call the manufacturer today to see if they have any ideas.

 

[Kevin54]

Page 11 shows the "flash" and it's meaning for ones that are curious http://www.mrheater.com/upload/newsletter/60016_mhu_hsu_45_75.pdf Page 14 is the failure to operate page.

 

[MXRACER]

It may take a while for the gas to get to the gas valve so the green flashing mat be a no gas error code. Also be sure you have the polarity correct.

 

[dipper]

Ground should be connected to screw attaching to the metal frame inside the access panel. I found the transformer to be the best place.

The slow flash is normal operation. They also indicate in the instructions how to reset the board by turning the t-stat off then back on; or power cycle the heater. It could
be that the gas line hasn't been bleed enough to get the gas to the heater.

Read up on the instuctions again and call the mfr if you still have problems.

 

[dipper]

Also be sure you have the polarity correct.

In this installation, i don't think the polarity will matter as long as the t-stat is hooked between R and W on the heater control board.

 

[Junkman]

You should hear the discharge fan go on, and then the igniter should start sparking, even if there is no gas in the line. It will take a few cycles to purge the air from the gas line. After two attempts to start, you have to reset the unit by unplugging it or turning the thermostat to its lowest setting and then back to calling for heat. You must break the call for heat to recycle the electronics, so if your garage is extremely cold, then the thermostat might be calling for heat even if it is set at 40 degrees. For this reason, I installed my thermostat slightly twisted to the side so it no longer reads properly at temperature, but doesn't call for heat when the garage is at 30 degrees.

 

[Red Green]

I think Junkman is right that you need to unplug the unit for it to reset the system. Is the next step.

 

[400excracer]

I tried calling the manufacturer at lunch and I was on hold for about 35 minutes and gave up. Tonight I will try grounding it and resetting the system and if that doesnt work I'll call in a professional. Thanks for all your help guys. Once I get it all figured out I will post pics of the install and my garage.

 

[Junkman]

No need to call a professional.. You have all the professional help you will need here. This is the busiest time of the year for heater manufacturers, and they are swamped with calls from people that are having problems. Don't get discouraged, because it is probably a very simple fix. I had some problems with mine originally, but in the end, I was able to get it working.

 

[Red Green]

Once again Junk beat me to the punch. It almost has to be something simple.

 

[Junkman]

As long as the punch isn't Jim Jones Cool Aid, we are all safe....

 

[dipper]

You could eliminate the t-stat and just twist the two wires together and see if that gets you going. Maybe something is bad with the t-stat.

 

[bomber]

I had the same problem -- it took quite a while to get gas to the heater -- about a half dozen connect, try, disconnect to reset, connect try cycles . . . . . .

Doulbe check your power conenctions, as well -- the instructions on mine were just a wee bit fuzzy, and I wound up having to swap one connection -- fired right up!

 

[dipper]

there are a couple of wires twisted together for the black and *********** to connect too. Make sure you don't have any loose wires in there that didn't get connected.

 

[MXRACER]

In this installation, i don't think the polarity will matter as long as the t-stat is hooked between R and W on the heater control board.

I meant the polarity on the 110 volts not the T stat, I found this out the hard and cold way LOLOL Trust me the polarity on my Reznor needs to be correct !!!!!

 

[krooser]

Do you have a inline pressure regulator? Many heaters will not lite without one...

 

[400excracer]

No I dont. I havent had a chance to get out there and mess with it at all. It has been really cold here the last week and I have been busy with Christmas stuff. I am planning to work on it tomorrow. Have any of you guys with Mr Heaters had to use a pressure regulators??

 

[dipper]

No, i didn't need a pressure regulator. I think there is an adjustment on the gas valve inside the heater but it's set at the factory. You shouldn't need to mess with it for most installations. I would just keep resetting the unit by power cycling and seeing if it will start, it's probably just not getting the gas yet.
The slow flash about once per second indicates "normal operation".

Get the heater going and it won't be really cold out there. ha ha

 

[Junkman]

Crack open the gas line and allow some gas to escape. Then it should light. Just don't allow so much gas to escape that you blow yourself up when it does light. Propane is heavier than air, so it falls. Natural gas is lighter, so it rises.

 

[dipper]

Good advice Junk. Just open it for 5-6 seconds to bleed out. Then wait 15 minutes before igniting to let the gas fumes escape.

 

[D KRAGER]

Do you have a inline pressure regulator? Many heaters will not lite without one...

Are you running nat gas or propane?

If you are running propane you MUST have a regulator!!!!!!!

The wrong gas pressure will cause the gas valve to not open.

 

[dropride]

You can get a regulator from home depot, tractor supply, etc.

 

[400excracer]

I am running natural gas, so hopefully I wont need a regulator. I will be working on it today.

 

[400excracer]

Well guys, I think that I am going to have to call in a professional. I tried cycling power at least a dozen times and I got nothing. Not every time, but about half the time when I unplug it I hear a switch. The board is still flashing slowly. The thermostat is hooked up correctly at the thermostat and the white wire is hooked to W on terminal on the board and the red wire is hooked up to R on the terminal on the board. A guy that I know who is a heating and cooling guy told me to un hook the gas line as close to the unit as possible and make sure that I have gas and not air, which I did. Plenty of gas. Any other ideas guys??? Help!!!!

 

[wqqdy3]

I bought the same heater a month ago but on propane. The first time I started it worked fine. The next time, it is doing somewhat the same as yours. The LED flashes slowly but the vent fan would start, but would make no attempt to start. I could get it going by cyclying the power on and off and can usually get it to start on its own after 5-6 attempts. I was able to get through to the tech line and after describing my problem they sent me a new circuit board (yet to install). I found it odd that they recomended to replace the panel even though there is a code for circuit board failure. I'm wondering if they had a run of bad circuit boards.
Good luck

 

[400excracer]

I am beginning to think that I need a new board too. I tried calling their tech line today but they were closed. They are open tomorrow till noon so I will try to call them and see what they come up with.

 

[wqqdy3]

I think I have the direct phone line number to one of the techs. I had to call back with a serial number before they sent me the part. I think its on my desk at work. I've got to go in and get some tools for a home project, I'll check then. At least that it will get you past the switch board.
Jamie

 

[400excracer]

I think I have the direct phone line number to one of the techs. I had to call back with a serial number before they sent me the part. I think its on my desk at work. I've got to go in and get some tools for a home project, I'll check then. At least that it will get you past the switch board.
Jamie

I appreciate the help, but I actually got through to someone this morning after waiting on hold for 20 minutes. As most of you thought it was something simple....bad thermostat. The tech had me take the thermostat off and twist the wires together (like someone here had suggested and I didnt do because I couldnt believe that a new thermostat was bad) and the blower motor came on right. It ignited a few seconds later and tada!!! Heat!!! I am so excited that I can go out and work in a heated garage this winter. I will post some pics up shortly. Thanks everyone for all your help. Well back to the garage!!!

 

[Red Green]

Glad to hear you got it working and didn't have to pay a professional to tell you the thermostat was bad.

 

[400excracer]

Thanks Red Green. I love it. I still have to install my 8' flouresent lights, install a sink, and insulate the attic, but at least I can go out and use it now.

 

[Junkman]

I appreciate the help, but I actually got through to someone this morning after waiting on hold for 20 minutes. As most of you thought it was something simple....bad thermostat. The tech had me take the thermostat off and twist the wires together (like someone here had suggested and I didnt do because I couldnt believe that a new thermostat was bad) and the blower motor came on right. It ignited a few seconds later and tada!!! Heat!!! I am so excited that I can go out and work in a heated garage this winter. I will post some pics up shortly. Thanks everyone for all your help. Well back to the garage!!!

Just because it is new, doesn't mean that it will work. I prefer used parts that are time tested.

 

[400excracer]

Just because it is new, doesn't mean that it will work. I prefer used parts that are time tested.

I know that as well as anyone since I used to assemble machines and we commonly had new parts that didnt work. This thermostat was so basic that there wasnt much to go wrong with it. I have a programable thermostat from my last house that I kept, but I cant for the life of me find it. Until I find it I think that I am just going to wire the two thermostat wires together when I need to use it.

 

[Junkman]

For garage thermostats, just think of KISS............