Laars endurance EBP

Paul S_3

Having a slight problem with this type of boiler.....customer has heat and hot water now....but there are intermitting problems with heat shutting off....display says F5 tank sensor error.....THE PAPER WORK SAYS TO CHECK SENSOR @ 77F IT WILL READ 10,000 OHMS.....THE BOILER IS AT 170F AND IM READING OVER 1.4 MILLION OHMS....do i have to drain down boiler and take sensor out and get sensor to 77f....or is there a chart with ohm readings at different temps???.....has anyone experienced these types of problems with these boilers?...

thank you PAUL S

pipeking

can u

post a pic of the sensor where it goes into the tank? i wouldn't think u have to drain the boiler to take it out.

Paul S_3

pipe king

Pic of sensor

Tom_133

Ive done this

wrong a couple of times, if what I am seeing in the picture is the sensor in the lower tank than you dont have to drain it but you will get water. I did this once and I assumed if I shut off the supply and return on the domestic side I could swap it quick holding a bucket under it. So I prep'd the new sensor and had it ready to go, unscrewed the bad sensor and then took a 180 degree 1/4" stream of water to the crotch!! Got a little hot on my hands and the boys! Didn't get at the time shutting the domestic valves did nothing for me. If you can Isolate the expansion and go quick you may not need to drain the tank. if the boiler has been out a couple of days it wont be that hot