XSeries-forum

well, another puzzle, the heater on my x3, 3.0i stopped working yesterday, and at the same time the lpg stopped as well, a think the prins system has a temperature sensor, and i feel there may be a link, i recently added radweld to the system as i lost about a cup of water every couple days, any ideas folks, rgds david

Check the temp gauge, if it is not getting up to temperature the heater will not blow warm, as there is insufficient heat in the cars coolant to transfer to air in the heaters matrix. Also the LPG system has a temp sensor in the gas vaporiser that switches it over to gas when coolant temperature get hot enough. This prevents the vaporiser freezing up, I believe. If the temp gauge is reeding low due to a stuck open thermostat, that would be your cause.
Other heater problems can be caused by a faulty Final Stage Resistor ( Hedgehog )
Are the fans running, is it the engine coolant temp. Are there any lights/ display ?
Loosing water, is there any visable White smoke at the exhaust, a blown head gasket can cause the heater to pack up too.
Take the radiator cap off when the engine is cold, is there any excess pressure, water being pushed out?

thanks for the reply, no smoke or marg in the rocker box, rad gets hot, and the temp guage runs bang in the middle, but i now suspect i have a blocked heater transfer hose from which i think the lpg sensor is, i,m having the whole cooling system flushed, and refilled, and we,ll go from there. i think the radweld may be the culprit, ho hum, rgds dave

Auxiliary water pump is Your problem, get it checked.

found a local garage, S.MAX, young fella is really interested in the job, he was all over it, turns out a tiny almost invisible split in the expansion tank, last owner i guess like me put some sort of sealent gunk in the system, this blocked the heater hoses, new tank, a good flush, bingo, sorted, what a carry on, thanks folks for the advice, onward and upward, rgds david