munchkin f02 advise

clammy

Went today and looked at a munchkin that has been going off on f02 requiring reset ,checked the circ which operated fine and the supply sensor was replaced ,checked the wiring which was fine no lose wires or lose connections had 5 vdc on the sensor wire also .Cycled the unit at least 1 dozen times and could not get it to code ,the installation was fine about 5 years oid the unit has not been cleaned and as things are i doubt the HO would cough up a check for the cleaning also since the boiler was installed the basement has been finished and there was alot of evidence of sheet rock dust ,I did pull the board out and blow the termials free of dust ,any other ideas ? I did sub this job for some one but i was never conntacted to do any service or maintance on the unit it seems everybody thinks that the yearly maintance should be free hahaha thanks for any other opionts and i did contact HTP peace and good luck clammy

Steve Whitbeck

Munchkin

What boiler do you have and what year was it built?

If it is a T50 or T80 and built in 2004 - use a CO tester and with the boiler running at high fire check for CO leakage between the insullation and the inside back of the boiler - Bad connection at the back of the heat exchanger.

That boiler should be cleaned every year.

It may just be a bad sensor.

How is the boiler vented?

Are the aluminum parts getting cloudy or are they still shiney?

I always suggest that the exhaust outlet be at least 18 inches higher than the intake or at least 6 feet horizontally.

I snorkel the exhaust up about 18 inches and then put a 45* on top with the SS screen in it.

If you are getting reversion it can make the boiler do all kinds of things.

If the 925 control gets corroded from reversion the boiler will throw out all kinds of false codes.

clammy

no signs

There are no signs of any corrision or re circulation of flue gases ,all the terminals on the board  did not show any signs of corrision ,the venting is up to snuff pvc ,terminating  about 30 inches from the ground 2 inch pvc with them seperated about 14 inches apart tee on the intake ,straight out for the vent ,the unit was built in 2005 ,i know it is in need of a good cleaning ,flue temp seamed to be fine there is no discloarazation of the pvc ,I will go back with my anylizer and check for any leakage on the rear of the unit i did not think of it at the time nor have my anylizer with me at the time ,my friend did order and change the supply thermister,the 925 controller functions fine and all the perimeters (supply ,return ,flame sensor reading)seem to be operating fine ,we did ohm out the supply sensor wires and they where fine ,the boiler is not running away temp wise either it's max temp for hot water prodution is 180 and for heating 165 the boiler seems to only do off when running for the indirect.As i stated earlier i just installed it 5 years ago working for a buddy i advise him to tell them to get them serviced each year i cannot force him nor his custermers to have the servie done and i don't think i should have to do it for free ?I am the one with the anylzer not him and on another note this custermers brother burned my buddy for a big chunk of change and she is a real slow pay so who knows if he may totally blow her off but he usually always does the right thing and gets it you know where .Tough world if we go back again i will check it with a anylzer thanks for your insight peace and good luck now i am off to go fishing clammy

PORKCHOP

FO2 LOCKOUT

THE FO2 IS RESPONDING TO THE SUPPLY WATER TEMP.  BE SURE YOU HAVE PRPOER FLOW THROUGH THE PRIMARY PIPING.  YOU SHOULD HAVE A PRIMARY PUMP THAT IS OPERATING ANYTIME THERE IS A CALL FOR HTG. OPERATION.  THIS IS ACCOMPLISHED THROUGH THE TT CIRCUIT.  THE SUPPLY AND RETURN TEMP SENSORS ARE THE SAME PART JUST HAVE A DIFFERENT COLOR WIRE CONNECTION.  YOU CAN MAYBE SWAP THE TWO SENSORS AND SEE IF THE CODE GOES TO F03,  IF SO YOU WILL KNOW IT IS THE SENSOR,  I HAVE HAD WHERE THE PRIMARY PUMP AND THERMISTOR WERE BOTH A PROBLEM.  THE SENSORS ARE FAIRLY CHEAP AND EASY TO INSTALL.  PROBABLY CHEAPER THAN REPEATED SERVICE CALLS.  ALSO AS A REGULAR MANTENANCE THE HEAT EXCHANGER NEEDS TO BE CLEANED YEARLY ESPECIALLY IF USED TO HEAT DOMESTIC HOT WATER AND HOME HEATING THE MORE OPERATING HRS. THIS BOILER SEES THE INCREASED BUILD UP IN THE HEAT EXCHANGER WHICH WILL EVENTUALLY LEAD TO BUCKING THE HIGH LIMIT.  THIS SYSTEM IS REAL EASY TO CLEAN. 

HOPE THIS HELPS

PRK CHOP