Gas boiler blower motor

Glen_7

Posting for a friend. When the power was switched on to the boiler this season, everything seems to work fine but it was noticed that the small black motor (blower?) runs constantly even when there is no call for heat and no flame being generated into the fire box (forgive the lay terms). Is this normal? I would think it would prematurely wear out the motor. Thank you.

unclejohn

Not normal, most likely a stuck relay.

Abracadabra

Always? as in 24/7? Power burners are setup for prepurge which runs the blower motor to clear out the combustion chamber.

Glen_7

So they had a pro come by and told them the gas gun was an older obsolete unit and said they could remove it and send it to somebody who might be able to fix it for $1,100. Since it was indicated by another post here that this is a relay issue, are relays internal to this type of burner or external? If the latter I would have to wonder what the "pro" was talking about. Thanks.

JStar

Get another pro.

Tim McElwain

That is an Economite E-20 gas conversion burner which was installed many years back to replace an oil burner. The E-20 works as follows:

On a call for heat the thermostat is connected directly to the tray or in some cases the thermostat powers a relay which then is tied to "T T" on the burner tray. That activates a relay on the tray which powers the burner motor. As the motor gets up to about 3/4 speed a centrifigual switch in the motor closes and powers the gas valve which is part of the conversion burner. and a pilot then lights the burner.

Based on what you are saying is happening it needs a new black box RBM relay which can be changed in the field as it is mounted on the tray assembly inside the MIDCO E-20 burner. I have a parts list for these burners and would suggest contacting Midco who is located in the Chicago area and still makes conversion burners. If you want the parts list contact me at gastc@cox.net.

Tim McElwain

Midco Info

Midco International, Inc.
4140 West Victoria Street
Chicago, IL 60646-6727

Toll-Free: (866)705-0514

Toll-Free Fax: (866)580-8700

Telephone: (773)604-8700

Fax: (773)604-4070

Get model and serial number off the burner.

Steamhead

Look closely at that boiler- it looks like a Peerless JO or TW series unit. This series of boilers is built like a tank, but needs a burner that can produce enough static air pressure to move enough air for good combustion. On oil, with the usual Beckett AF or AFG, they often soot up. The best oil burner for one of these would be a Beckett NX, Carlin EZ or Riello, all these can move the necessary combustion air against the resistance in the boiler.

On gas, the Midco E-20 has the same issue. An evolution of the old Lo-Blast burners, it can't move much air in this type of boiler. Even the newer Midco EC series burners, as nice as they are, would probably have trouble on one of these boilers. A digital combustion test would probably show poor combustion results, possibly including high carbon monoxide. Ask me how I can be so sure of this............

if the boiler is in good shape, it makes sense to upgrade to a Carlin EZ-Gas burner, which can overcome the boiler's internal resistance and produce better combustion. Another advantage of the EZ-Gas is that its control system can shut off the gas in less than a second if the flame fails or doesn't light, whereas the standing pilot system on the E-20 might take up to three minutes to shut down.

If it were mine, I'd do the upgrade.