Cabin heating problem

Hi,
My Y reg Series II heating has started playing up. Nothing seems to happen heat wise, then if I'm lucky, heating will just start working after several miles, also stops working sometimes with only cool air coming through, temperature control sometimes seems a bit wayward too. Would anyone know what the cause might be?
I don't know how the system works but wondered if a heat exchager or similar might be showing early signs of failing, or perhaps there is some obvious fix I'm unaware of. Any insight/ideas/suggestion is appreciated.
Thanks, DL

I'm sure you'll get much more expert answers but to state the obvious have you checked the water level in the expansion tank.

If it has got low at anytime there might be an airlock.

Do u have aircon with digital display or the classic type?

Do as advised and check the water level WHEN COLD, run the engine up to temperature with the heater set to hot, this should help to get rid of any airlocks.

If you still have a problem you may need to get you radiator flushed through and checked that the 'fins' are not blocked with mud if it has been used off-road at all.

Let us know how you get on...

There are two aluminium pipes attached to the the heater assembly which are connecting the matrix to the cooling circuit. When the engine is hot the coolant is constantly circulating through the heater matrix pushed by the pump regardless of the internal setting. Identify these pipes and put your hands on them, if they are both warm and the temp gauge is staying nice on the middle then the coolant flow is good and it means there is some problem with the heater assembly....i asked about the aircon thing cos this one has a diagnostic procedure with fault codes shown on the display...if no aircon and the coolant flow is OK u'll have to get to the heater assembly to phisicaly check it... remove the glovebox

sierrafery said:

Do u have aircon with digital display or the classic type?

Click to expand...

It has air con with digital display.
Many thanks for your help

Maybe u'll get an answer running the manual diagnostic then >

Feeling a bit stupid, it was low water level causing the problem, everything back to normal now. And will be checking the WL often for any obvious leaks.
Many thanks for everyone's input, fantastic.

DiscoLass said:

Feeling a bit stupid, it was low water level causing the problem, everything back to normal now. And will be checking the WL often for any obvious leaks.
Many thanks for everyone's input, fantastic.

Click to expand...

Easy done, exactly the same on mine addition of less than a litre of coolant and the heater function returned