Problem with new hot box after two hours of use.

I got to use the new Largo 12v hot box today. For two hours. I set it to 80 degrees to see how that did and ran it until I noticed it wasn't getting hot at the wand. I looked at it and bumped the temp to 90 and it started working. Not for long though. I finally got up in the back of the truck and tried bumping it again just to see what it did and nothing. The blower is running so I assume that I will need to check either the igniter or the thermostat. I just can't believe I only got a few hours out of it before it went down. I finished the job with cold water and will be looking at the issue tomorrow.

welcome to the themostate eating burners mine did the same thing not sure why that is but i fixed mine with a digital one however when you pay that kinda money for something its disappointing.

What digital did you put on and where did you get it?

Auber electronics from ebay

These are suppose to be some of the best

http://www.maxthermo.com.tw/ENG/html/product/p1532.html

Talk to Mike Wooley, he can get one for you.

If you want to make sure its the thermostat just bypass and connect the 2 leads together to complete the circuit. This will confirm it is the thermostat, not the flow switch, or anything else.

These seem pretty cool. Does anybody know which one we would order to replace a thermostat? Is Mike Wooley a distributor and with who? Do any distributors on this form carry a digital thermostat?

http://www.auberins.com/index.php?main_page=page&id=16

Brad that the company i use very good digital themostates.

Thanks Hal.

Here he is, looks like I forgot a letter, sorry Mike

http://www.propowerwash.com/board/upload/member.php?11283-AquaMike

Roy Sanders said:

I got to use the new Largo 12v hot box today. For two hours. I set it to 80 degrees to see how that did and ran it until I noticed it wasn't getting hot at the wand. I looked at it and bumped the temp to 90 and it started working. Not for long though. I finally got up in the back of the truck and tried bumping it again just to see what it did and nothing. The blower is running so I assume that I will need to check either the igniter or the thermostat. I just can't believe I only got a few hours out of it before it went down. I finished the job with cold water and will be looking at the issue tomorrow.

Click to expand...

I've got a Largo 115 volt 8-12 GPM horizontal hotbox that I purchased 6 months ago but never even used (or even started up) until Thanksgiving day (a couple of days ago). I hooked it up and the first thing that happened was the pressure relief valve blew and water started spewing out at full force. After much research and talking to the dealer I found out that just tightening the Allen screw on the relief valve would solve that issue. I tried to start the burner up again today and got nothing at all. No fuel pumping to the burner, no blower blowing, no igniter igniting, no heat, just cold water going through a coil. What a bummer this Largo unit has been!!!

I've had the hotbox on my trailer for 6 months but have been swamped with residential work so I had put off even starting the burner up at all. Didn't even put fuel in it until a couple of days ago. I've got some work to do at a hospital so I finally fueled it up and found out that the thing is broken from the very start. I'm guessing that the on/off switch/thermostat is defective. The red reset button on the burner pops out within seconds after turning the burner switch on. Very disappointing to say the least.

Just prime the fuel pump an she should take off when they run out they can be a bit hard to get re primed.

Thanks Hal,

I've located the bleed valve on the fuel pump. I also found a video on youtube showing how to bleed or prime the fuel pump on an oil burner. Hopefully good to go.

I appreciate your help. Thanks so much!

Why would you have no blower blowing thats odd?

If the reset button on the motor is popping out, the fuel pump may be locked up. Open the ignitor and see if you can spin the fan by hand.

Roy, did you try calling who you purchased it from?

The motor could be shot if left to the elements as well. The motor turns the fan + fuel pump, not motor no fuel. Also don't know what 120v source is, but if it can't keep up with startup of the burner that will pop out the button as well. Largo only makes the exterior and the coil, everything else is equipment you get on any burner.

I have had a largo 120v for 4 years now, still running the original ignitior/blower/pump, third flow switch, 4th thermostat. Once this thermostat goes though I replace it with the one I mentioned above. Easily 5000 hours on this unit

Doug Rucker said:

Roy, did you try calling who you purchased it from?

Click to expand...

No I figured it out. I first tested the thermostat and ignitor. Both for good. I had fuel in the tank but not enough I guess. Couldn't tell just how much by looking in even though I could see fuel. Evidently that wasn't enough. I put in a little fuel and it fired right up. I inquired about a fuel gauge cap but since the tank fuel fill sets at an angle to the tank they can't make one that will read accurately I am told. If this happens again I will gauge the fuel with an aluminum rod I have sitting next to it. I am curious how much it will read.

I would have never posted that LOL.Thats a big sigh of relief on your part i am sure.

Kiloman said:

I would have never posted that LOL.Thats a big sigh of relief on your part i am sure.

Click to expand...

Hey, live and learn. There was fuel in it so I didn't think twice about it. It was only after checking the thermostat and ignitor that I thought I would put in a little more fuel just to see by chance. Sometimes it's the stupidest things that kick your ass.

Russ Johnson said:

If the reset button on the motor is popping out, the fuel pump may be locked up. Open the ignitor and see if you can spin the fan by hand.

Click to expand...

Russ, I opened up the ignitor and the fan spins freely. I then plugged the power cord into an outlet in my garage and still the fan did not come on. I checked the circuit breaker that is built into the power cord plug and it was tripped. I reset the power chord breaker and now the fan does come on. Sounds like I may be in luck and just need to prime the fuel pump to get everything going.

I had tested and reset the power chord breaker yesterday when I was trying to get this burner going. Maybe I couldn't tell that the fan was on due to the generator and pressure washer engines making so much noise. I had even put my ear against the blower motor and couldn't tell that it was running. Evidently the fan was running then but just not audible.

By the way Russ, I got your phone message after I got in from a concert at church tonight. I didn't want to call you so late in the evening but thank you so much for calling me and offering your help in getting this burner running. If I can't get the burner running after priming the pump tomorrow morning I'll give you a call. I'm amazed that a person as busy as yourself would take valuable weekend time to call someone and offer your professional advice. Thank you so much!