I have a 4 year oldmonitor 2400 which has been totally reliable until recently. I have been through the error 14 stage with dirty filters at the tank and at the heater as well as running out of fuel. This problem is error 13 where the unit fires up for approx 2 minutes then shuts down, I removed and cleaned the flame rod detector which seemed to eliminate the problem for about a week although the dealer says that is never the problem, I tried plugging into a different outlet (ground problem?) which seemed to work for about a week but now its back to the 2 minute shut down. I'm at my wits end but I really, really don't want to throw away an $1800 dollar heater for something that is probably so simple.
The manufacturer has been totally unhelpful and although my local distributor is trying his best, he says it probably has to be totally rebuilt.
When it does run, it has a beautiful wide, ble flame.
Help!!! Cold.....

Here is a copy of your owners manual. Copy to your computer for future refrence. It will take awhile to DL. Note air bubble in fuel line will cause shut down at different times. Great heaters.

http://www.monitorproducts.com/pdf/manuals/m2400.pdf