adjusting water temperature with on-demand Precision Temp

[nickclifford]

Hi all,
any tips on adjusting water temp with an on-demand heater? I think I've found the issue but maybe some other ideas would be helpful.
My 1972 trailer has the original bathroom and a blend type water faucet for the shower, the water from the Precision Temp is VERY hot but when I blend in colder water, it shuts off the hot water So shower goes from dangerously hot to cold, no in between.
Solution? Two taps? that way could leave hot water on full & adjust cold tap for regulating the temperature? Not ideal for boondocking I guess ..
I'd have to find the water pipes and plumb in new lines, taps and shower head probably. It would be impossible to get behind the existing faucet without significant work, pulling out the tub and with the brittle plastics is would be a disaster.

thoughts ?

[rmkrum]

Did you set the heater control knob to “summer” setting per the manual? That may reduce the temperature some. Also make sure the debris screen in the shower head is clean so you can get adequate water flow.

Also, I found that a cheap water pressure regulator does not work well with my PrecisionTemp unit. I went to a Camco adjustable pressure regulator with a gauge on it to get better flow. Also check the debris screen in the AS inlet fitting for blockage.

I do have a two knob faucet for my shower/lavatory sink. I turn the hot water on full blast, then adjust the cold water for temperature. The ‘blend’ faucet may be part of the problem...

Admittedly the tankless is a bit touchy, but DW loves her Long hot showers, so we are good with the quirks.

[nickclifford]

Originally Posted by rmkrum

Did you set the heater control knob to “summer” setting per the manual? That may reduce the temperature some. Also make sure the debris screen in the shower head is clean so you can get adequate water flow.

Also, I found that a cheap water pressure regulator does not work well with my PrecisionTemp unit. I went to a Camco adjustable pressure regulator with a gauge on it to get better flow. Also check the debris screen in the AS inlet fitting for blockage.

I do have a two knob faucet for my shower/lavatory sink. I turn the hot water on full blast, then adjust the cold water for temperature. The ‘blend’ faucet may be part of the problem...

Admittedly the tankless is a bit touchy, but DW loves her Long hot showers, so we are good with the quirks.

thanks for the tips, it used to work , something has happened. I tried using city water & with the water pump. might be a new shower head ..? I need to find that summer setting but have never changed it before and only use in the summertime anyways

[nickclifford]

I found the red nob for high/low gas input (you'd think they have that marked, but easy enough to see !) seems to be a balance between water pressure & gas input. water pressure at kitchen faucet is low, so gas input needs to be higher to trigger the heater to come on, and still tricky to moderate overall water temp

[rdb504]

Hi,
I have a Girard brand on demand water heater in our 73 Ambassador, and we have a temp adjustment knob. Until I found a video online about the proper way to use, had the same problems you describe. We use full hot water in the shower, and adjust the heater, not mixing cold, I guess the water takes the path of least resistance. Either way we have been on the road since December, and love being able to take unlimited hot showers if I choose to.