I have a squealing noise that effects my heat while squealing.

Belts are new. Noise coming from engine compartment

Recheck belt tension and if that's okay , next would be to observe and try to narrow down the area it's coming from. May be a component bearing going bad.- Can remove belts and check each pulley.

Is a belt being to tight going to effect my heat the way it does.

From your description 'when it STOPS squealing the heat does fine' I'd say the water pump belt is slipping ror the water pump is ready to lock-up. BOTH can be VERIFIED before wasting money on the wrong stuff!!