Heater failure

[Paulguy]

Dear all. Can anyone please advise. Our 2017 Ducato multijet heater is blowing cold air. Also the outside temp indicator is showing high temps 50 - 70° ( actual outside temp approx 5°)
The engine temp gage is showing normal operating temp & the coolant levels are OK.
Does anyone know what the problem could be. Your advice would be much appreciated

 

[pappajohn]

Possibly either the temp thermostat for the heater matrix (not the engine one) or the water flow valve itself has failed......most likely the thermostat.
No idea where either are but the thermostat could be in the air ducting

 

[Spanner]

At the back of your engine there are two coolant hoses that pass through the bulkhead, supply and return for the heater, once up to temperature both hoses should be hot to the touch, are the hoses getting hot ?

 

[Paulguy]

Not sure on the hose temps I'll have a check tomorrow. Thank you for the comments

 

[Spanner]

Not sure on the hose temps I'll have a check tomorrow. Thank you for the comments

At this time of year it’ll take a long time for the engine to come up to temperature while stationary, best take it for a 5 mile run then both heater hoses should be very hot to touch and your heater should be blowing hot air

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[125BEER]

Ours took ages to get warm on Friday when we left.

 

[Paulguy]

OK thanks for the tip. I'll come back to you tomorrow. Thank you

 

[donkey]

I don't think there will be a heater water flow tap. Most modern vehicles have full flow through the heater and control the cabin temperature outlets via flaps, which divert the hot or cold air up, down or face vents.
It is possible one or more flaps are not moving, for whatever reason. Probably, if you lay on the cab floor with a torch and look behind the dash you may be able to see if this is the case, while someone operates the heater controls.

Geoff

 

[Paulguy]

Checked both heater hoses through the bulkhead & both are hot.

 

[SandraL]

Fiat external air temp sensor. Usually found in wing mirror on fiat cab.
On our 2013 A class I could not find it, not in wing mirror as not supplied by fiat, it was faulty so I wired in a new thermistor, an NTC 10K at 25deg C, B3800 or B 3950. This worked for us getting dash display external temp correct again.
If your van was clever and it thought external air temp was 70 deg C would it just bring in external air to heat the van?? Thats a guess and may well be wrong!
If you were a member you could access the resource section, in there is the fiat converters manual which details wing mirror and temp sensor wiring.

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[jockaneezer]

I had similar in an old Mk 2 Escort, one of the duct hoses had come off under the dash and it was blowing a gale of freezing cold air.

 

[BwB]

Has you van got the manual heater controls or the automatic version? The auto climate control systems can throw up a few problems which will need a dealer to look at (Fiat/Peugeot/Citroen). I've spoken to several owners who've had a few problems with their climate control.

In respect of the wrong outside temperature reading, you've not set it to Fahrenheit by mistake?

 

[Spanner]

Checked both heater hoses through the bulkhead & both are hot.

Providing your heater was working properly until recently and with hot water flowing through the heater matrix I guess the problem is almost certainly the flap mechanism that diverts incoming air over the heater matrix, when the control knob is turned to the hot position the flap is not moving, sometimes this can be a foreign part has found it’s way into the mechanism or the cable has become disconnected.
Vehicles with climate control are more complicated but I doubt your van will have that feature.

 

[Spanner]

Apparently climate control is an option on later Ducato vans, a decent diagnostic tool should find any present faults, if the outside air temperature sensor is faulty and reading high then the air con compressor maybe running flat out trying to bring the temperature down to the temperature shown on the heater control display

 

[cyberyacht]

I have the same temperature controls as immediately above but it never seems to warm the cab up much. I did have an external sensor that produced a false reading but, even after replacement, OH still complains and often has a rug round her legs.

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[donkey]

I have the same temperature controls as immediately above but it never seems to warm the cab up much. I did have an external sensor that produced a false reading but, even after replacement, OH still complains and often has a rug round her legs.

My heater is different, but I do have a Wife like yours.

Geoff

 

[minipoppy]

Dear all. Can anyone please advise. Our 2017 Ducato multijet heater is blowing cold air. Also the outside temp indicator is showing high temps 50 - 70° ( actual outside temp approx 5°)
The engine temp gage is showing normal operating temp & the coolant levels are OK.
Does anyone know what the problem could be. Your advice would be much appreciated

Hi did you get your heater sorted if so how did you fix it I have the same fault on my ducato thanks