Replace my aquahot 375 help

Since you have some hot water, the most common cause of lack of floor heat is the 2 brass check valves stick. This happens on all Aqua Hots if the floor heat system is NOT run once a month to keep the valves from sticking. Usually you can POP the valves with a hammer to free them up. The other cause, since you stated blue coolant, would be the Circulation motors have frozen/locked up or are just not working. But, if the fluid is NOT the correct Propylene/Glycol that is required, NO service contract will pay for repair. If you have the wrong coolant, you will have to completely flush the system, which is time consuming and expensive if you have to pay someone to do it. Then you will have to replace the Circulation motors which I would not trust after wrong coolant contamination. Parts are still available from Aqua Hot. Doug