Positive pressure

[Darren]

I did a 3-family house today with a single 22 year old oil fired hot water heating system. The unit did not fire-up due to no oil. The seller called for service and with-in 2 hours, a technician showed. During the period he was on site, we went over the various problems with the unit; Leaking TPR, leaking cirulating pump connection, missing screws on the vent pipe connections, open gaps where the vent pipe enters the chimney and more. It's clear the service company (who has a maintenance contract) has not been doing their job.

I pointed out to my client there was no barometric damper installed on the unit. The technician stated, in front of everyone that a damper is not needed due to positive pressure, and installing one will allow spillage into the house.

Now, correct me if I'm wrong, but a damper is needed on any oil fired appliance; the damper needs to be adjusted properly so it will only open when needed. I took my client aside and told her to ask for a report from the service company stating a damper is not needed. Was I wrong, is the technician full of it?

Darren

[Terence McCann]

On a furnace/boiler that vents to a chimney, yes.

On a mid to high efficiency furnace/boiler that sidwall vents, no however, check with the manufacture for correct installation procedures on this application.

[Rob Amaral]

There are some H.B.Smith boilers that don't have to have a baro damper. Some of those Italian jobs don't as well...

[Erol Kartal]

I thought side venting was restricted to direct vent/high efficiency furnaces?

Erol Kartal []

[Jim Katen]

Originally posted by Darren

I did a 3-family house today with a single 22 year old oil fired hot water heating system. The unit did not fire-up due to no oil. The seller called for service and with-in 2 hours, a technician showed. During the period he was on site, we went over the various problems with the unit; Leaking TPR, leaking cirulating pump connection, missing screws on the vent pipe connections, open gaps where the vent pipe enters the chimney and more. It's clear the service company (who has a maintenance contract) has not been doing their job.

On the other hand, if that's the worst stuff going on with a 22 year old unit, I'd say the thing was doing quite well.

I pointed out to my client there was no barometric damper installed on the unit. The technician stated, in front of everyone that a damper is not needed due to positive pressure, and installing one will allow spillage into the house.

Hmm. I'm not sure about the 'positive pressure' part. Did they have units with positive pressure in the vent back then? I've certainly never seen one. Seems to me they all had negative pressure in that era.

Now, correct me if I'm wrong, but a damper is needed on any oil fired appliance; the damper needs to be adjusted properly so it will only open when needed. I took my client aside and told her to ask for a report from the service company stating a damper is not needed. Was I wrong, is the technician full of it?

Darren

Sorry, Darren, you're wrong. Not all oil-fired units require a barometric damper. Certainly most of them from that time did, but not all. You've got to check the manual.

- Jim Katen, Oregon