Hi, I have a 6 year old Envision WaterFurnce model NDV049A111CBR. Closed loop system with long runs in ditch, not drilled. Dual pumps are 230 volt. Current (normal) draw is about 1.2 amps each. Both fuses in the 230v source are 10 amps each. Both fuses blew the 6th of Jan. No a good sign so I called the service tech (Furnace still in warranty). I thought there was an extremely good chance one of the pumps was shorted or just locked up. The service tech replaced both fuses and the pumps started and ran OK. I was surprise but not convinced anything was fixed. This past Sunday, both fuses blew again. The tech had installed 10 amp glass fuses instead of the original ceramic, I don't have reason to believe that's why they blew again but it was sure easy to tell they were blown without anything more than a look. Both were very well burnt inside the glass. I bought some 10 amp ceramics after the Jan problem so I installed them last night and all is well again. I expect need shut down to occur even sooner. I apologize if my explanation is too long, just wonder if anyone with experience see's this as a trend and have an idea of what the real problem is? FYI, The DHW pump was and had been turned off before the fuses blew this second time. Is this not surely a sign of a bad pump/s? Thanks for any help!