I have a brand new (less than 11 hours) Little Giant 4HT HP propane water heater and it is giving me problems. When I ignite the pilot light it has a good strong pilot light flame and will stay lit as long as you have propane. When you turn the unit to the on position it fires the burner and then all of a sudden when the burner shuts down the pilot light goes out with the burner which basically turns the unit off. It may go for 10 min without shutting down and may go 5 the next time after I restart it. It has even gone through 2 or 3 cycles of heating and the pilot stayed lit during those cycles. I called Little Giant this morning and Scott told me my regulator was too small to provide enough propane. I was running a 350,000 BTU/HR regulator and switched to a 1,000,000 BTU/HR today. After the switch there is no difference in the problem, still exactly the same. Basically the pilot tends to go out when the burner shuts down, I don't know if the burner is shutting down because it reached temp or something else. I can only clean 1/2 a room and then I have to go out and check the burner to make sure it is still going every time to maintain heat. really getting on my nerves. I need to get it fixed by Monday as I have a very busy day and my first clean is for a business owner / property owner's personal house ( he does over 25k a year with me) and it has to be done Monday morning.
Need help with 4HT Little Giant
- Thread starter KBRENNY
- Start date
Leslie Judson Jones
Member
- Joined
- May 12, 2007
- Messages
- 2,242
call me i know what to do, it's a easy fix.. thanks LES 864-233-6442
Les hit the nail on the head, the pilot light assembly on the 3ht is the same as the 4ht. The difference in updraft from a 3ht to a 4ht is huge. This causes the pilot flame to "pull away" from the thermocouple. It does not got out because of the air movement but once it is pulled away from the thermocouple long enough the control valve thinks there is no pilot light flame and shuts off propane supply completely.
I adjusted the pilot flame strength, realigned the flame splitter ( small shield that sends half the flame to the burner and half to the thermocouple), and tweaked my pilot orifice a little. Ran 35 gallons through the system at 550 psi with a wand jetted at five #2 jets, cycling 10 second on and 5 off. I did this until I ran all 35 gallons through. Average temp 235 deg atm, usually would kick in at 231 and turn off at 237. The funny thing is the burner only kicks on a split second after the wand valve is opened, and shuts off a split second after it is released.
I adjusted the pilot flame strength, realigned the flame splitter ( small shield that sends half the flame to the burner and half to the thermocouple), and tweaked my pilot orifice a little. Ran 35 gallons through the system at 550 psi with a wand jetted at five #2 jets, cycling 10 second on and 5 off. I did this until I ran all 35 gallons through. Average temp 235 deg atm, usually would kick in at 231 and turn off at 237. The funny thing is the burner only kicks on a split second after the wand valve is opened, and shuts off a split second after it is released.
Kevin B
Member
Greenie, you gotta get your wands to my distrib. I'm an impulse buyer! haha, I think scott thought I was nuts when I asked for 03 jets 5 months ago. Told them today it was the best thing I have ever done.
Time to get a greenhorn, but I have to get tile stuff, and prepare my bank for winter. Hopefully I can slip some stuff on this years expenses.
Time to get a greenhorn, but I have to get tile stuff, and prepare my bank for winter. Hopefully I can slip some stuff on this years expenses.
Shawn Forsythe
RIP
Check the available gas pressure AT THE BURNER to determine if you have a drop below the permissible minimum at the moment the thermostat initiates the heater to fire. I looked at your setup picutes and the hose between the regulator and the heater is prohibitively undersized. Any length or plubing turns is going to lower gas pressure immensely, and thus proper flow. The pilot will "wink" out almost immediately if the gas flow is restricted below a certain point.
You can sometimes compensate for restricted plubing by the adjust-ability of the regulator, but too small a hose is usually beyond anything you can adjust for.
Ideally the gas regulator is NOT located at or near the tank itsel, but much closer to the heater, just under the floor of the van. While some might think that they want to put the regulator in the protected environment of the van itself, it is unsafe to put the regulator within the passenger compartment. Most people want to put the regulator at the tank, for plumbing simplicity and their idea to minimize the lenght of the high pressure section. In practice, this won't work because of the precipitous pressure drop on the low pressure side.
Use at least 5/8" ID hose on the low pressure side, and minimize plumbing turns to an absolute minimum. Test pressure at the burner should be at least 11" water column. Little Giant prefers 13-17", if possible, but you won't find many regulators that will go up that high.
You can sometimes compensate for restricted plubing by the adjust-ability of the regulator, but too small a hose is usually beyond anything you can adjust for.
Ideally the gas regulator is NOT located at or near the tank itsel, but much closer to the heater, just under the floor of the van. While some might think that they want to put the regulator in the protected environment of the van itself, it is unsafe to put the regulator within the passenger compartment. Most people want to put the regulator at the tank, for plumbing simplicity and their idea to minimize the lenght of the high pressure section. In practice, this won't work because of the precipitous pressure drop on the low pressure side.
Use at least 5/8" ID hose on the low pressure side, and minimize plumbing turns to an absolute minimum. Test pressure at the burner should be at least 11" water column. Little Giant prefers 13-17", if possible, but you won't find many regulators that will go up that high.
The regulator is a 1,000,000 btu/hr capacity, The hose is 1/2" and the regulator is mounted directly under the heater under the van. Les was dead on with his assesment, the updraft was strong enough to pull the pilot away from the thermocouple. If I was using the Little Giant supplied vent cap there would be enough air flow restriction to prevent that but I have it vented to the outside of the box with a 6" duct and little if any restriction there. I ran the unit after the little tweaks and it rocks. Les actually asked me about the vent cap first and knew the problem before I answered. It is great to have a place like this with so many combined years of experience to have for information.
