Garage heater

[sshephe6]

Hello to all, I'm new to the Garage journal.
I have a question and in need of some advice, I just finished up installing a Mr heater in my garage. I ran about 90ft of 3/4" black pipe and the yellow plastic tube with risers on each end for underground. I'm confident in all my work, but when the heater turns on the burners only turn on for about 2minutes and then stop. The question I have is there a pressure gage I can install inline to know what my gas pressure is at the furnace. I would like to know this before I contact the manufacture.

Thanks for any and all advice
Steve

 

[finn]

Water manometer (not a gauge, but a real manometer) is available online.

I think I paid $18.00.

 

[dave67fd]

Maybe I'm reading your post incorrectly but you ran 90' of black iron pipe underground?

 

[p_mori7]

Did you purge the air out of the line before trying to fire it up ?

 

[CNGsaves]

MORE DETAILS NEEDED.

Is the 90 ft NG supply run directly after meter so you've got best pressure possible?? How many elbows, 90's etc over entire run??

Why did you decide to go with 3/4" as it likely is small for that length?? So is most of that 90 ft the yellow plastic buried pipe (how many feet)??

What is Btu of heater??

Any other demands on that 90 ft NG supply pipe (ie hot water heater in garage, pool heater, etc)??

To measure your pressure, all you need is T near the heater and 1/4" NPT adapter to handle a low pressure gauge (water column) as pictured below. This is VERY NICE example which is WIKA brand - - - $58 at Amazon. It's nice since it's 0 to 15 (with graduations every 3" of WC) so your sweet spot of residential NG pressure of 7 or 8" WC would be up near top of gauge.
http://www.amazon.com/dp/B002089PIS/?tag=atomicindus08-20

 

[jgump]

Is the board flashing? If I remember correctly on my 75k I had to modify the burners since it was tripping the lower switch. They have instructions for this.

 

[jgump]

http://www.garagejournal.com/forum/showthread.php?t=27597

in this thread are the instructions for the burner fix.

 

[sshephe6]

Thank you everybody,
No There is not 90 ft of black pipe underground. There is about 5" of black pipe inside the house, about 75 ft underground and another 10 ft or so in the garage and there are 3 elbows in the line,oh the heater is 80,000 btu's. No other demands. As to why I went with the 3/4 I tried to get quotes and one of the heating guys said he would run 3/4?.

 

[LS6 Tommy]

I hate to be the bearer of bad news, but you can't use regular old black pipe for direct burial. Now, onto your operating problem. If it runs for two full minutes, you should have adequate gas pressure. 3/4" line is more than enough volume. When the burners go off, does the fan keep running? Do you have to reset anything or do you have to wait any length of time before you can get them to relight? You may have a limit or rollout switch issue. If the T-stat is a mercury type, it has to be level. It may also need to have the heat anticipator set.

Tommy

 

[sshephe6]

It turns out there was a loose wire, it has ran the rest of the with no problems!!!!

 

[freebirdwelds]

Thank you everybody,
No There is not 90 ft of black pipe underground. There is about 5" of black pipe inside the house, about 75 ft underground and another 10 ft or so in the garage and there are 3 elbows in the line,oh the heater is 80,000 btu's. No other demands. As to why I went with the 3/4 I tried to get quotes and one of the heating guys said he would run 3/4?.

That black pipe underground is a nogo.

 

[Lassen Forge]

You can't use black iron as DB for anything unless it is specifically designed (eg coated externally and rated) for DB. You can't fake this - so yeah, it's worth it to pull the "normal" black pipe out now and replace it with something rated for DB Gas service... When we had our gas like installed we not only had epoxy coated (yellow) iron pipe but it was double wrapped as well.

You do NOT want your gas supply line to rust, but normal black iron will do just that (with extreme prejudice) - she will rust, then she'll leak, then captain, it canna take it no more and she gonna blow...

 

[PoorUB]

Reading comprehension is low in this thread!

 

[mrb1]

Reading comprehension is low in this thread!

There was a scam post #11 early this morning that has since been deleted by mods. That's what got the 10 year old ball rolling again

 

[4x4Pete]

The iron pipe has since rotted away and became a nice big gas fire pit........