Flutter sound - Martin Propane Direct Vent Heater MDV20VP

loltun9

Just installed this heater and had propane company come hook up the propane line to it. He did a pressure test and adjusted the pressure at the main pressure valve per heater recommendations. It has another pressure valve closer to the unit (maybe 7-8ft) and he didn't do anything with that one.

I Ran the heater for a few hours and didn't notice anything out of the ordinary. It had some initial burnoff smell and some crackling/popping sounds as the metal heated up. Temps were mild today only in the 50's.

After about 4 to 5 hours running it, when I was outside by the vent, I noticed a sound coming fromm it that was hard to describe. I thought it was muffled rattle type sound but soon realized it sounds more like a flutter.

When inside and listening to the unit it seems to be coming from the area where the exhaust tubes are located (Outer tube has air intake that surrounds an inner tube which is the exhaust). The pilot flame looks consistent and good from low to high settings.

It seems to have more flutter at lower temps and even with the burner isn't going, only the pilot vs when it's turned up higher...but that could also be because the gas and unit is louder when it's running high and I just can't hear it as well. As soon as I turn off the pilot, it goes quiet.

I've kept it off because I don't know what damage I could do not knowing what the issue is. Any ideas before I pay the propane service tech another $100 to come look at it? Thanks

retiredguy

You did not say the size of the heater or the propane tank supplying that heater. If the propane tank is too small, the tank pressure could fall below the required minimum inlet pressure for the device. As you use the propane gas for the heater more gas is evaporated from the liquid which causes it to cool and lower the tank delivery pressure.

loltun9

Sorry about that. It's a 20,000 btu heater and it's hooked up to a 320gal propane tank that has 2 regulators running. Propane tech checked pressure at first gauge at the tank, but that's it. When I told him it needed to be adjusted to 11 to 13 WCs based on the manual specs, he said we don't do that, we do pounds. It's getting 20lbs of pressure.

EdTheHeaterMan

There are different parts of a profane gas company. The drivers of the deliver trucks. The technicians that do the tanks and first stage pressure regulators. The guy you need is the one that connects the appliances. they have the gauges the do the inches WC. they also have more experience and may even do furnace and boiler repair that include controls, heater piping and circulators and even some ductwork to swap out a propane furnace from time to time. The smaller LP gas companies may not have the appliance tech. All they do is to shut off the gas if there is a problem with an appliance that they feel is not safe to operate.

Depending on your LP supplier, you may or may not need to get an HVAC service tech. Call the Gas supplier and ask for appliance service on a space heater. If they don't ask them if they can suggest someone they know is good at fixing Space heating appliances

loltun9

Thanks @EdTheHeaterMan. The propane company I used, is the place I rent the tank from. I told them specifically what I had installed and needed it hooked up to the propane line already coming through my wall and adjusted to the right pressure for this heater. I'm waiting for the manager who is in charge of installation/repair crew to call me back. I'm not sure they have all those different kinds of technicians, but will ask. When I spoke with him the first time, before he sent the guy out, he just said ok, Ill send out "Bob." I appreciate this insight. I assumed since they hook wall heaters up all the time around here they would be well versed in 'adjusting' new ones they hook up at the time of service. One shouldn't assume.