Heater question

Low on water in the radiator,
Partly pluged up heater core.

undeperforming water pump or loose pump belt.

Could also be vacuum related, whether an engine problem or a faulty or partially crimped line, not having enough to hold the gates open at idle, effectively closing the ducts.

I am reading up on this and read it could be air in the system. The recommendation is bleed or "burp" the cooling system. The factory service manual I found on-line has detailed instructions on how to do this. I'll give that a try this weekend. Might replace the belt too, while I'm at it.

From what I understand, the 95 model Villager's blend doors aren't vacuum controlled. I put some coolant in the recovery tank and heating improved. Still checking it out. I found the engine air bleed bolt and heat pipe bleed cap and read up on bleeding the system. I'll try it soon.