Recirculation system configuration with tankless/solar system

eluv8

Without knowing more about the piping layout, try turning on the shower and watching the boiler. My guess is its turning on and off. What is your setpoint on the Takagi? Often times you can lower the temp to 115 and mix less at the shower to solve min flow problems. If that doesnt fix post piping layout.

The Dentist

Recirculation system configuration with tankless/solar system

Solar HW heater pre-heats for a Takagi M-1 tankless.
Recirculation line from Takagi pumped by Grundfos pump.
Problems:
1)Uncomfortable temp fluctuation for first 5 minutes of shower
2)Takagi seems to run a LOT even when hot water not being used [yes, the recirc pipes are insulated]
3) Recirculation system is also plumbed back to the solar pre-heating system
So...
Shouldn't the solar pre-heat only go directly to the Takagi?
Is there some reason I don't know about that the recirc system needs to go back to the solar pre-heater?
Shouldn't the recirc system be as short as possible?
Any other ways to decrease run time on the Takagi?
Have considered 'demand' system, but don't want the wait and the hassle of more equipment.
Many thanks, folks.

Mike Dunn

solar w/tankless

Are the temps going up or down from setpoint?

Will your tankless allow flow without firing? If the solar preheat is already at the desired temp does the tankless still fire when it detects flow or will it simply let the water past until it is cool enough to warrant firing?

Just some thoughts?

Mike Dunn

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