Girard water heater—warm water only!

[Magnolia Tom]

For some reason our tankless water heater isn’t producing hot water, only warm water when we open just the hot side of the faucet. Checked propane, checked outside shower faucet was closed, and I’m at a loss. Shower was at best lukewarm (100F). Any suggestions as to what I need to check? Of course it worked perfectly last time out. Thanks

[Shokyle1]

Do the tankless have a bypass maybe it got move slightly

[Magnolia Tom]

I have never winterized so I doubt it

[Bookemdanno]

Just wondering & hoping that you got it figured out Tom?

[Magnolia Tom]

Originally Posted by Bookemdanno

Just wondering & hoping that you got it figured out Tom?

I think I figured out the problem....
One, the park water pressure fluctuates causing low flow. Two, and probably the real culprit is the shower valve on the shower tower I installed wasn’t completely on shower. It was on shower and partially on the hand held which was somehow mixing cold water with the hot. Kids showered tonight and they all said the water was hot. I’ll be showering in the morning to test it as well.

[Dskyward]

I had this same issue a couple years back, luke warm hot water, and we have the Truma AquaGo tankless unit. We were up north in Indiana and found out that cold water (50 deg tap water)was getting bled into the far hot position, like 15-20%. Cold was always ice cold, so...I just rotated the faucet 180 deg and problem solved. But now when summertime comes and our wellhouse pressure tank will reach 85-90 degrees water temp, it will be hotter water than this if someone wants a ‘cold’ shower.

One thing you must keep in mind with tankless water heaters, there is a minimum flow rate that triggers the gas burner and if you’re still having to mix cold water in, that cuts into the flow rate budget and can cut off the burner, so you have to keep the flow rate up to keep the burner going. For Truma, it’s .4 gpm. Early Girards I read was 1 gpm. I’ve no idea what rate they’re at now.