tankless hot water heater

[guspaul]

Does the tankless hot water heater on my 2015 greyhawk have a bypass valve. Is there anything special I have to do to it when dewinterizing it?

[Mountain Cajun]

It only has a drain and it drains the whole system. I blow my system out with the drain open. When in use the system has a thermostat that fires the burner when the temperature gets below 40 degrees to keep system from freezing.

[THE MEEKER]

There is no bypass valve but there should be a water shut off valve before the unit.

Turn off water supply at that valve. Open the taps so the system can drain and release the pressure from the plumbing system. Drain remaining water at the heater's drain valve.

It would be a good idea to use an air compressor to blow out any remaining water from the system.

Adding RV anti-freeze solution not recommended as it can cause damage to the tankless water heater's components.

[katiedog]

Make sure you turn on Power switch inside of Water Heater compartment.
It is part of the heating system to prevent freezing.
Check the manual

[jd99336]

This is a bit curious to me. I have found no valve to isolate the water heater (2016 Greyhawk) and while I blow out my system with air, I still follow with RV antifreeze. Guess I need to go find the instructions, but don't remember any caution on using antifreeze. I am 3 winters in with no adverse affect thus far....certainly hope I didn't mess something up. If anything, it would seem like the heater firing the burner on an empty tank could be damaging.

But...never had one before so may be wrong.

As for dewinterizing, simply run water through the system to purge air and antifreeze and you are good to go.

[jd99336]

From the Girard website:

Winterization can be accomplished using one of the two common methods ofwinterization used for RV water systems:

• Compressed Air method: Drain all water from the system opening one tap at a time and usingcompressed air to purge all remaining water.
• Anti-freeze method: Follow the recommendations of the Recreational Vehicle manufacturer and ill the system witha non-toxic anti-freeze. Make sure that the anti-freeze flows from each tap to complete the process.

Antifreeze Device [NOTE, THIS IS FOR OPERATING THE UNIT IN FREEZING TEMPS, NOT FOR WINTERIZATION]: If you wish to operate the water heater in potentially freezing conditions the model GSWH-2 has a built in thermostatthat will start the burner whenever the temperature of the Heat Exchanger falls below 38ºF and will automatically shutoff when it senses a temperature in excess of 58 º F

[Marshmellow]

I have a tankless water heater also 2013 Greyhawk. There is no bypass that I'm aware of and I use the antifreeze method. Turn the valves to winterize turn the filter on the connection backwards connect hose place in antifreeze and turn on taps until pink fluid runs from taps, flush toilet and don't forget the outdoor shower. Same as JD9936, 5 yrs winterizing this way and no issues. Dewinterizing; connect water supply open taps until water flows, turn taps to hot water side and should be good to go.

[pconroy]

Originally Posted by jd99336

From the Girard website:

Winterization can be accomplished using one of the two common methods ofwinterization used for RV water systems:

• Compressed Air method: Drain all water from the system opening one tap at a time and usingcompressed air to purge all remaining water.
• Anti-freeze method: Follow the recommendations of the Recreational Vehicle manufacturer and ill the system witha non-toxic anti-freeze. Make sure that the anti-freeze flows from each tap to complete the process.

Antifreeze Device [NOTE, THIS IS FOR OPERATING THE UNIT IN FREEZING TEMPS, NOT FOR WINTERIZATION]: If you wish to operate the water heater in potentially freezing conditions the model GSWH-2 has a built in thermostatthat will start the burner whenever the temperature of the Heat Exchanger falls below 38ºF and will automatically shutoff when it senses a temperature in excess of 58 º F

Lots of information posted here - but this is the one that matters if you have the Girard tankless.