No cabin heat

[nickharman]

Just got the R4 out the barn after 8 months. Took an hour to clear the brambles to get to her

Started on 4th spin!

But after a 30 min drive to town and back, no warmth in cabin

Thermostat stuck closed?

 

[jcarruthers2]

Hi

It could be the thermostat. Does the hose the thermostat is housed in get hot when the car gets up to temperature?

It could also be an air lock in the cooling system which would mean you need to bleed the cooling system.

 

[DAA]

the heater matrix could be blocked. But check all cooling system, it's a good ideia.

 

[JdeW]

Heater matrix could indeed be blocked (by the valve) or indeed have an airlock. Check by unscrewing the bleed nipple from upper small tube.
The thermostat has nothing to do with cabin heat.
You have to understand the cooling system.
First, on engine start the cooling pump circulates the coolant only throughout the engine or when you set the cabin heating on throughout the engine and the small cabin heating circuit.
Second, when the coolant temperature gets hot the thermostat opens slowly and the large circuit with radiator kicks in to cool the engine and ultimatly the fan kicks in.

 

[nickharman]

I’ve checked for airlock. None. There is some warmth on the floor but it goes cold on the demist setting. Is it possible to shut off the air completely as I’d rather have no air than cold feet!

 

[JdeW]

Normally air runs from the outside in through the big outer airflap which can be closed but not completely, and most likely extra air runs in through all the doors as the seals don´t shut properly anymore.
Could feet is always an issue as your feet rest on 1 mm of sheetmetal from the outside,
The Renault R4 heating system is one of the best, if not the biggest asset of the Renault R4, it is very good.
Either the cabin heater radiator blocks the flow or the heater radiator valve is stuck, find it out, replace the faulthy one and you should be fine.
Everything on the Renault R4 is a fairly easy DIY.

Heater radiator, suitable for Renault R4, from year of construction 1971 to 1990. Dimension: 147 x 138 x 42mm

Heater radiator, suitable for Renault R4, from year of construction 1971 to 1990. Dimension: 147 x 138 x 42mm No. 82140

www.franzose.de

R4, Heating valve. Suitable for Renault R4 (all models). Or. No. 7701007674.

R4, Heating valve. Suitable for Renault R4 (all models). Or. No. 7701007674. No. 82488

www.franzose.de

 

[Cowhorns]

Just got the R4 out the barn after 8 months. Took an hour to clear the brambles to get to her

Started on 4th spin!

But after a 30 min drive to town and back, no warmth in cabin

Thermostat stuck closed?

Dumb question but is the fan working ok? Does the heater radiator warm up properly top and bottom? If yes can you switch the radiator off as well?