swids

I have a 6 year old Sundance Capri.Displayed a watchdog error. Reset,water temperature display is not accurate.One time it will read in the 90's come back a while later it will read in 80's and now it says 106.When it is the range to call for heat the relays work, correct voltage on each leg, and both legs are pulling about 22 amps.Dsconnect and Ohms are 4. The return water is only luke warm not hot as normal. Seems like 2 problems but my thought is that they are probably related. Also would like to know how the thermostat is removed... Any suggestions are appreciated.....Thank You Steve