Doesn't have any. The system should self bleed.
You may have an air lock in the heater pipes some vehicles are fitted with bleed screws for this purpose.
should be tyre valve cap on heater pipes coming out bulk head on drives side
install a air bleed valve at the highest point,
its used to bleed air out of cooling system,theres another one near the bulkhead where the heater pipes go into the car!
You have air in the system you need to bleed it out. do you have a really old heater/ boiler. hot water heater need more info
how do I bleed water system on the 806 peugeot
Possible air lock in the heating pipes. Common after changing thermostat. look for a bleed screw on the heating pipes between the engine and interior, or loosen one of the heater pipes., after engine has warmed up. Run engine to dislodge trapped air.
The steam flows through a grill of pipes and the heat radiates from the pipes to the room.
Read the label. A gas heater will have three plumbing pipes connected.One is a gas supply. An electric heater will only have two plumbing pipes but it will have an electical conduit or electrical wire feed line.
If by "bleed" you mean drain, disconnect the lower of the two hoses (do not confuse with the pipes from the AC evaporator) and drain the coolant into a bucket. If you are flushing the system (which you should if you are changing the coolant anyway), dont bother draining it, most of the coolant will flow out anyway, just do the coolant flush and fill from the radiator.
to increase surface area
1- Drain coolant. 2- remove heater hoses from core inlet and outlet pipes in engine compartment. 3-remove screws and heater core cover. ( right side lower passenger compartment ) 4- carefully lower core out of heater unit. This old of a truck it would be wise to replace both heater hoses. Use antifreeze as a lubricant to install heater hoses to new core inlets.