Lochinvar water heater head scratcher

[Deleted User]

not making?

Jiggle the damper when found in this position and if it fires you win.

ME

Steve Ebels_3

Lochinvar water heater head scratcher

My brother in law, the farm supply guy, called to see if I'd look at a water heater for him last week. They installed this water heater when the farmer expanded his milking parlor last year. It's an LP gas fired CLR-199-100-DF9 and is the only thing connected to a 3/4" steel pipe approximately 30 feet in length from the regulator to the unit.

It worked fine for the first two months of operation and then began to exhibit a recurring problem. It would function normally for a few days then fail to fire for some reason. The farmer simply kills the 110 power to the heater and cycles it back on. It has never failed to light when doing this. First time, every time. When he comes in the barn and discovers there's no hot water, the vent damper is always in a vertical position indicating that it tried to light and failed. Water temp setting is about 170*.

I cleaned the pilot, igniter and checked the flame current. It measured 3 mA so the signal should be enough to hold the main valve in. Gas pressure is set at 10.5"w.c. on the manifold and remains steady when the burner fires. The barn has all new wiring and the ground path has been checked (by others), supposedly OK.

Told my BIL I'd post this problem here for him and see if anyone had an idea what could be causing this thing to fail to light. The problem is becoming more regular, almost daily, but it still fires right up when the line voltage is cycled.

Got any ideas?.......So far this week has been full of weird things like this and I really don't want to get into another one.

Ross_7

polarity

Try checking the polarity of the 110 vac going to the boiler. Just because it's new wiring doesn't mean it can't have problem. Check the flow switch, and make sure it's installed correctly.

Darin(in Michigan)

Humidity?

If the unit is near the milk room, there may be alot of humidity from the cleaning equipment. I've seen it before in flooded basements where the humidity wreaked havok on the flame sense ability of the control board. What to do to prove it? Don't have a clue:(

Darin(in Michigan)

Another thing...

Hi Steve. Hope your staying busy.
Something else. Is the condensor fans from the bulk tank pulling a negative pressure on the room where the water heater is(assuming they're in the same room). Just a thought.
Take care and talk at you soon.

Darin