aqua hot 600D code

[Greglc]

Hi,
Thank you for welcoming me.
I have an aqua hot that just gave me a code on my Pump 2 on my aqua hot of,,, undr crt,,, does anyone know of this code and meaning. I have all other pumps working properly on the aqua hot. all other zones were hot this morning except pump 2,,, the fans are working but no heat,, only on pump 2. I have electric and diesel switches on.
Any input will be much appreciated,, thank you.

[153stars]

You can download owners and repair manuals. Older manuals are in aquahot archives take a little more of a search to locate.
Educated guess the code is "under current" the pump may not be spinning / open circuit maybe, blown fuse. dislodged or bad relay. Stuck pump check valves have been brought up more than a few times. A couple taps on check valve have helped. I think the glycol can become sticky.

[vito.a]

You can download the Service Manual here:
https://www.aquahot.com/library.aspx