Install draft inducer or not?

[Adkjake]

I have a 3 story chalet style house, ground floor/basement it a walk out finished basement, main/2nd story is most of the living space, 3rd story is 2 small bedrooms at the peak of the roof. Part of the finished basement is the utility room which houses the oil fired boiler and hot water heater, attached is a copy of the set up. This system is not orginal to the house, it was installed 5 or 6 years ago and is vented to an outdoor clay lined cinder block chimney. Note, the woodstove is not connected to this chimney.The wood stove is on the main/2nd story and does a great job heating the upper 2 floors. As I don't use the basement much, except for entry and exit, I have a small oil filled electric radiator to keep it around 62*. Each floor has its own heating zone. Thus there is little call for the boiler.

Recently I noticed a fuel oil smell when the DHW and/or boiler fired up. This is my 3rd winter in the house, and since the boiler doesn't run much, I did not have it serviced this year on the advice of the tech who serviced it 2 years ago. Thinking there was a problem with one of the oil burners, I had the furnace guy take a look. Both burners were fine. He thought it was a venting problem. So, had my chimney sweep come over and take a look. The chimney was clean with no obstructions. His opinion was that because it is an outside chimney and temps have been in the teens, the cold air was keeping the system from venting properly. A cold chimney just doesn't draw as well. He also thought it should be about 6 ft higher perhaps, and that a draft inducer might be the answer. Where the galvanized stove pipe goes thru the wall is ground level.

For the past few days, I've shut the electric heater off in the basement and set the thermostat for that zone at 66*. So, the boiler now runs every couple of hours, at least for that zone. This seems to have
helped, I don't notice any fuel oil/exhaust smell.

What are folks experiences with draft inducers? How reliable, do they really work? Would I need 2, one for the boiler and one for HW? Not a whole lot of room on the vent pipes. Thanks for any input and advice

 

[taxidermist]

Is the chimney an outside chimney or does it run thru the interior of the house?

I had a close set up to yours and the chimney was 12x12 outside chim and it would get to cold to draft. I was told to install a chimney liner to make the flue smaller requiring less to heat up to get a good draft.
Rob

 

[Fred61]

I see that you have two appliances sharing the same flue. The draft from the water heater will be diminished because the flue will be drawing through both units even if only one is running. If they are both running you are still sharing the draft which may not be adequate to operate the individual unit. That said, perhaps a draft inducer will help.

 

[Adkjake]

I see that you have two appliances sharing the same flue. The draft from the water heater will be diminished because the flue will be drawing through both units even if only one is running. If they are both running you are still sharing the draft which may not be adequate to operate the individual unit. That said, perhaps a draft inducer will help.

1. Yes, it is an outside chimney. Not original to the house, added on when the heating system was installed.
2. Would you put the inducer on the hot water vent then?

 

[Fred61]

It's possible that if the inducer is only put on one unit, it could blow back down through the other causing flue gasses to enter the living space. If they were both operating and only one had the inducer, the other would be grossly affected. Don't know! If a draft inducer is installed at all, I would think it should be installed downstream of both units. Don't take my word for it. Perhaps more knowledgeable people or those that have experienced this situation will chime in with other opinions.

 

[tom in maine]

Here in Maine, two devices are not kosher into a single flue.

The fact it is vented into an outside flue compounds the issue as others have mentioned.
An ID fan would help, but it would have to be installed after the tee that ties the two flues together.
It does not appear that there is enough room for one.

An alternative plan would be to power vent one or both units. That does add more eventual service cost.

 

[BoilerMan]

I think that is only for different fueled apliances, ie. wood and oil.

Basically your house is a better chimney that your chimney, meaning that the warm air that is leaking fron the house in the uppermost floor is pulling cold air down the outside chimney and some flue gasses with it. This is common with an outside chimney which is cold unless there is a lot of heat exhausted into it on a periodic basis. Extension of the flue (adding to the top of the chimney) will help, and if that does not solve the problem and you still want to burn oil in that setup, a draft inducer after the two appliances converge into the common flue is needed. It would be set to come on if either the Bock water heater of the Burnham (looks like one) boiler fire.

TS

 

[Fred61]

I respect TS's opinion and he is basically confirming my thoughts so I would place the inducer, if you decide to install one, after the two appliances. If there is not enough space you will just need to re-route or re-arrange the flue pipes. The "cold flue" theory discussed above in a "little used" flue makes sense.

 

[Adkjake]

I respect TS's opinion and he is basically confirming my thoughts so I would place the inducer, if you decide to install one, after the two appliances. If there is not enough space you will just need to re-route or re-arrange the flue pipes. The "cold flue" theory discussed above in a "little used" flue makes sense.

Thanks TS and Fred, good advice. Yes, it is a Burnham Boiler, and using oil is pretty much all we have. That or the 3rd highest electric rates in the state. No natural gas within 100 miles, propane is only other choice and a poor one.

That would be ideal if one could be installed after the "T" for both vents and set up to run when either or both fire.

Although, I may just keep monitoring it for awhile, having the basement zone heated by the boiler seems to have solved the problem. Haven't noticed any smell since I've done this. I'll also montior oil use to compare against the cost of the electric heater, which was about $50 for the 30 days from late Nov. to late Dec

 

[TheMightyMoe]

Those chimneys just suck the cold right in, a inducer or a insulated / higher stack seem like the answer you are looking for. As mentioned above.

Also seems like you MIGHT have room to clean up the venting a bit, the less 90*s / angles, the better your draft is going to be.

 

[chimneylinerjames]

Is there a rain cap on the chimney? Sometimes I have seen chimneys without rain caps have this issue and installing a rain cap stops maybe the slightest amount of wind blowing down the chimney. This is just a simple cheap possibility you could try.

 

[Adkjake]

Is there a rain cap on the chimney? Sometimes I have seen chimneys without rain caps have this issue and installing a rain cap stops maybe the slightest amount of wind blowing down the chimney. This is just a simple cheap possibility you could try.

MightyMoe, I was wondering if I could insulate and enclose the chimney, perhaps use foam or greenborad insulation and cover with same sidiing as on the hous, T1-11. How much heat would that help retain?

"CL-James"- No rain cap on the chimney, I mentioned it to the sweep, he didn't seem to think it was big deal. But, I'm with you, couldn't hurt and does elimnate the chance of rain, snow, leaves, pine needles and critters getting in there

 

[chimneylinerjames]

I was wondering if I could insulate and enclose the chimney, perhaps use foam or greenborad insulation and cover with same sidiing as on the hous, T1-11. How much heat would that help retain?

Instead of insulating the chimney itself, it would be better to install a chimney liner and have the liner insulated. Seems like less work and cost than insulating the chimney itself. Definitely faster to install the liner.

 

[TheMightyMoe]

Instead of insulating the chimney itself, it would be better to install a chimney liner and have the liner insulated. Seems like less work and cost than insulating the chimney itself. Definitely faster to install the liner.

^^^

 

[BoilerMan]

I was thinking about this today, and was working at a jobsite in the basement. They had an outside chimney (fireplace) and a second flue for the oil furnace, low and behole there was a draft inducer on the system. If I had a camera phone I'd have snapped a pic. Simple system, tjernlund inducer simply cut a slot in the pipe aster the two apliances converge, and wire up the inducer with two independent relays for burner isolation. If either or both fire, the inducer runs, I'd install it first before any more expensive modifications to the flue itself if your smell problem persists.

I'd also invest in some CO detectors if you don't already have them.

TS

 

[tom in maine]

I am pretty sure that two devices, regardless of the fuel type into a single flue are not allowed.
Is it a big problem? Maybe not, but it complicates potential problems.

Another solution could be a top of the flue pipe ID fan. This will always positively vent the system. They ain't cheap and service puts you at the top of the chimney.

ID fans cut into the side of a vent pipe and not very good, but might do enough to keep things moving in the right direction.