Tankless water heater troubleshooting

[Austinwoodham96]

I have the st60 suburban instant water heater. Keep getting error code E1 about 5 times until propane ignites and hot water comes. Also the kitchen island will only activate water heater to send hot water once I've turned on bathroom sink and it ignites. Won't give hot water at island until then. Anyone have same issue or some insight?

 

[BryanValRox]

Well, I did a quick search and can’t seem to find an official troubleshooting manual on the ST60, but another model indicates it could be gas starvation or even air that hasn’t purged from the line. I would think that this would only be likely to happen on the first attempt after turning the gas on, on a given trip.

As far as the activation concern, this type of heater requires a minimum flow demand (measured by an internal flow sensor) to fire, I am seeing flow rates listed anywhere from .5 to .75 gallons per minute, so my guess is the flow rate of the kitchen faucet doesn’t meet the flow requirement by itself and the additional flow from the bathroom sink gets things to fire off. Wondering as an test, if you remove the kitchen nozzle, and let the hose free flow if it will fire off. This would validate my theory if the hose can free flow the needed gpm without the nozzle in place.

 

[Austinwoodham96]

Well, I did a quick search and can’t seem to find an official troubleshooting manual on the ST60, but another model indicates it could be gas starvation or even air that hasn’t purged from the line. I would think that this would only be likely to happen on the first attempt after turning the gas on, on a given trip.

As far as the activation concern, this type of heater requires a minimum flow demand (measured by an internal flow sensor) to fire, I am seeing flow rates listed anywhere from .5 to .75 gallons per minute, so my guess is the flow rate of the kitchen faucet doesn’t meet the flow requirement by itself and the additional flow from the bathroom sink gets things to fire off. Wondering as an test, if you remove the kitchen nozzle, and

Well, I did a quick search and can’t seem to find an official troubleshooting manual on the ST60, but another model indicates it could be gas starvation or even air that hasn’t purged from the line. I would think that this would only be likely to happen on the first attempt after turning the gas on, on a given trip.

As far as the activation concern, this type of heater requires a minimum flow demand (measured by an internal flow sensor) to fire, I am seeing flow rates listed anywhere from .5 to .75 gallons per minute, so my guess is the flow rate of the kitchen faucet doesn’t meet the flow requirement by itself and the additional flow from the bathroom sink gets things to fire off. Wondering as an test, if you remove the kitchen nozzle, and let the hose free flow if it will fire off. This would validate my theory if the hose can free flow the needed gpm without the nozzle in place.

I live in mine full time so the problem is a everyday nuisance. Any tips on purging the lines of air, or would it be purged already after I've used propane stove? Check the flow rate with a manometer? Maybe pick a high flow faucet for the kitchen sink?

 

[BryanValRox]

Well, given that your living full time, I wouldn’t think air would factor in unless there is a LP change out or change over , or shut off event. Once the line is purged of air, it should be good to go until the system is opened to atmosphere for whatever reason. The next logical check would be to validate your LP pressure with a manometer to be sure you meet the requirements in the attached document. Personally, I would concentrate on getting the water flow increased first, and reevaluate if the problem still exsists. Looks like your ST60 is calling for a min. flow of .70 gpm(see attached) . Maybe the control board is seeing the lower flow and attempting to start the fire process and errors out(only a guess).
Just a reminder, if your not comfortable working with LP , call in a pro. Guess, I should also say that LP HOSE ID could be an issue, remember pressure is pressure, BUT volume of flow is a separate measurement. Meaning, you could find you have the correct pressure, BUT LP flow volume could still be low if the hose is under speced.

 

[Mike in North Wales]

Check the faucet for proper flow. If you haven't already, take the head apart and remove any debris from the cartridge. Ours was full of PEX plastic shavings.