No heat low r no heat and coolant dissappears

1) Coolant tank may show full but radiator is low in coolant...Cold engine...remove cap...inspect coolant level in radiator...fill if necessary,,,
2) If #1 is OK, the coolant system has an air blockage...With cold engine remove cap...Start engine...Heat control on high... when thermostat opens coolant AND air will escape from radiator...there will be coolant loss...Wait until all air escapes then carefully replace cap...When engine cools remove cap and top off coolant if required.....saailer

I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867

Where is your coolant going is the biggest problem you have to fix first. You may want to look at the water pump too.

Fill the radiator and coolant reserve tank to MAX level.
Low coolant will cause low to no heat.

If coolant is over 2 years old then you should do a coolant flush

Heat and air conditioning are in separate systems. If you aren't getting heat, the first step is to check your coolant level. Low coolant can result in improper flow through the heater core. If you do have low coolant, be on the lookout for a coolant leak! If your coolant isn't low, then there is going to be an issue with circulation through the heater core. The heater core could be clogged in some way or another.1

I would take your vehical to a local service station its possible your coolant is leaking internally inside your engine and possibly mixing with your engine coolant, I feel this is because you are not seeing any coolant on the ground underneath your car, the coolant is dissappearing rather fast, if i were you i wouldnt drive the car at all in the risk that if the coolant is mixing with your engine oil this could severly damage critical parts of your engine, they usually will perform a series of tests in a case like this such as pressurizing the cooling system and a possible leak down test on the engine to see where the coolant leakage is occuring and what the proper repair course would be to take....

sounds like low coolant to me

could be a cracked block engine.what i would do is put a tarp or old sheet down park vehicle on it and wait then when you check you can look on old sheet to see where its leaking and it will give you an idea where to look for the leek if it was head gasket youd have sludgey looking whitesh foam in the oil

Check the coolant level. If it is low, the heat won't work at idle, only when accelerating. If it gets even lower, it will overheat.

You should see heat well prior to this heat, is your coolant level exceeding low? I have seen situations where the coolant level is so low it will not get to the heater until it warms up (by warming up the coolant has expanded thus filling up the heating system more.
I hope this may have helped,
Tom

your carb has a coolant heated choke system if i am correct as car warms up the coolant warms the choke spring. keep full of coolant to keep from other damage