Interior heater type - what is it?

[Eccles60]

Can any of the Renault experts out there please tell me if the heater in 4 is water or air blended? Specifically, does the heat control on the dashboard operate a water valve or does it move flaps allowing air to pass through the heater matrix?

Why do I want to know? Why not? Seriously, the Haynes manuals always say put the heater on to drain or fill the cooling system but on an air blended system it's not necessary other than to be able to tell there's water in the matrix from the hot air being emitted from the heater. With a water blended system however, it's essential to put the heat to hot.

I'm bored, can you tell?

 

[jjad]

I'm no expert, but I'm pretty sure that the heat control turns a water valve on/off, allowing/preventing water to flow through the matrix.

 

[Andy McGhee]

The top lever controls air flow; the knob lower down (with the blue and red dots) controls the flow of water.
These photos may help:

 

[Eccles60]

View attachment 23989

The top lever controls air flow; the knob lower down (with the blue and red dots) controls the flow of water.
These photos may help:

View attachment 23990
View attachment 23992

I think you are saying it's a water blended heater, i.e with a water flow valve. This is sort of implied in the Haynes manual but I can't see a diagram of it (and certainly no internal drawing of it).

Thanks for your reply.

 

[benchseat]

It is water. The two hoses connect to the coolant circuit. Haynes say "turn the valve on" to prevent airlocks (and in a small engine like the R4 the volume of the heater matrix is a significant proportion of the whole i.e. more serious if air-locked).

 

[Eccles60]

Thanks, very helpful and interesting. Cheers!

 

[JdeW]

It is water. The two hoses connect to the coolant circuit. Haynes say "turn the valve on" to prevent airlocks (and in a small engine like the R4 the volume of the heater matrix is a significant proportion of the whole i.e. more serious if air-locked).

Luckely it is a car-coolant heated heat exchanger, and the interior heating capability is enormous, especialy in winter time, and that for a none insulated car.
I always found it the best accesory in the R4 beside it's very realible engine and superb suspension.

 

[Eccles60]

Luckely it is a car-coolant heated heat exchanger, and the interior heating capability is enormous, especialy in winter time, and that for a none insulated car.
I always found it the best accesory in the R4 beside it's very realible engine and superb suspension.

Although an air blended system is more controllable, less prone to water leaks and what most manufacturers fit these days...

 

[angel]

With an air blended heater you need very good thermal insulation of the air flaps and the heater box itself, among others. On the R4, with the rudimentary air control flaps, the heater matrix directly behind the heater box, and no form of heat insulation for the matrix itself, you would have two options "warm" and "hot", while in hot summer days the options would be "hot" and "sauna". We are expecting 40 deg.C here later in the day, so I'm glad I can completely cut off hot water flow to the heater .
Air blended heaters became standard in automotive industry on vehicles fitted with automatic air conditioning because it's far easier to control warm/cool air flow with servo motors moving flaps, than moving a water valve.