Water temp wont go past 90 degrees

It's to dam cold outside, you will never get to temp with that outside temperature, leave the cardboard on and she will come up to temp it will take a while...

RADIATOR NEED TO BE FLASH ALSO REPLACE OR REMOVE THERMOSTAT.

Thing is that there's very low temperature from heaters if cardboard isn't there

NEVER REMOVE THE THERMOSTAT, just keep the cardboard there, bottom line is sucks living is a cold climate