My old Grundfos pump was in disuse for a few years and then needed to be replaced in a workshop/guest house building. I got a new one installed by a plumber. Its not a digital model.
The hot water heater is about 50 feet away from the sink with hot/cold water taps.
With the pump OFF, its taking 3-4 minutes for warm water to start coming out of the hot water tap, and this is with the hot water heater turned up to HIGH. My washing machine is next to the hot water heater and the water coming out in the machine is hot.
With the Grundfos pump ON, its taking 2-2.5 minutes to get warm water to start coming out of the hot tap, and a bit warmer by 3 minutes of running the water, but never really hot.
In the past, my old Grundfos seemed to get the hot water coming out in less than a minute.
The plumber was puzzled about why the water wasn't hot, but i am concerned about why its taking so long. I did 3 comparative tests.
Does this sound normal? Any thoughts?
Thanks.

impossible to answer without knowing how the system is piped.
what you are describing does sound wrong.

YOu need to purge/flush the recirculation line. After not working for so lone it could either have an air bubble or some accumulated debris. Either one would prevent proper circulation.

Thank you for you reply.

I called my plumber again to see what else we might try to fix this.
He thought cold water was mixing into the hot line somehow, and had me turn off the water valves to the washing machine to see if that was a factor. That did the trick! Now getting warm water faster and hotter water than before. He's going to put something on the lines to stop it mixing in.



Edited 1 times.

How are the hoses attached to the washing machine, because that cannot happen with the usual washing machine valves.