Brrrr... FM4 cold start issues

[John Mitton]

So this is my first winter with the FM4 out by the garage, and it seems that the colder it gets, the more false starts it requires. After starting for moment the indicator lamps rotate red, green, yellow a few times before settling on a blinking green. At that point I can again try to start it.

Tonight I hooked up at 14F and it took about 6 or 7 tries before purring along for (what I hope) will be a full fill overnight.

Anyone else experience this?

[Timon]

Re: Brrrr... FM4 cold start issues

What about adding some water pipe heating tape around the pump head? It might be enough to keep it from false starting. Of course I'd check with Fuelmaker about this as you don't want to interfere with the temperature compensation system.

[holtek]

Re: Brrrr... FM4 cold start issues

I don't suppose your tank just happened to be completely empty? The fuelmaker systems will shut down if there isn't a sufficient pressure rise detected within a specified tiime frame. On cold days, this would be more likely (PV=nRT). After a few start attempts, enough pressure will build up in an empty tank and you can fill as usual. I had a situation where my crown vic was completely empty, and it took 100+ restarts to get my phill to keep pumping! Fuelmaker's advice if this happens is to get a partial fill at a service station. GRRRR!

I think a FM4 fuelmaker has a DIP switch setting for "cascade fueling" that would eliminate this nuisance.

[John Mitton]

Re: Brrrr... FM4 cold start issues

Mystery solved...
I have two furnaces in my house and realized that the FM4 (now upgraded to an FM-Q2-36) shuts off when both furnaces are running -- especially with some added draw on the gas line from the water heater for good measure. Poor old FM was simply not getting the pressure she needed.

Now I do what I should have been doing all along... turn down the thermostats at night when we are sleeping. My reward is not only lower gas bills but a full tank in the morning too

Ah, how I pine for spring!

[cnguser]

Re: Brrrr... FM4 cold start issues

Two options I have run across:
1. Get one or both furnaces replaced with newer high efficienecy ones with modulating burners - once the house is warmed up, mine cycles on/off only on low flame, allowing my FMQ-2 to stay on line day or night.
2. Contact your natural gas supplier for a meter upgrade to higher capacity.
You will need to run a separate line from the meter to the fueler, and it will need its own regulator. The house gas appliances will need to feed from another regulator, but both regulators can feed from the single larger meter simultaniously. May want to have a heating contractor install the piping for you, etc.
(I was going to do this until getting a new furnace as noted above).