We've been installing Peerlees MI series boilers in residential applications for at least 4 years now and have found them very reliable except for one part - the flue draft damper. I've had 5 or 6 of these fail within the last year where either the damper blade itself gets hung up before opening 100% or the microswitch doesn't want to close when the damper does open without wiggling it around a bit. On one boiler even the replacement damper we installed failed. All of the venting was double checked in each instance and no problems were found. In every case the boilers were connected to properly sized chimney liners, had short length well pitched flue runs, no evidence of condensation and ample combustion air was present.
All the dampers that have failed are standard Effikal models ranging in size from 5" to 7". I've asked two of our suppliers that sell Peerless boilers if they have heard of anyone having problems with these dampers and they all swear that we're the only one - which I am now really finding hard to beleive. I'd hate to switch boilers just because of this damn damper, but we're really getting sick and tired of late night warranty calls to jiggle a damper. Is there anyone else out there who has experienced problems with Effikal dampers on any brand boiler?