About 7 years ago I had a high efficiency gas furnace installed. The installer also placed a small vent pipe in the chimney to help the water heater create enough draft. Last year my old water heater died and I replaced it with a standard gas water heater. Up to this point I've had no problems. This Spring, I had higher radon readings so I had a radon mitigation system installed and it's been working great. Just the other day I was looking at the water heater and noticed a warm draft coming from the exhaust pipe (water heater not running). So I watched a couple videos on how to check to make sure I had proper up draft. I didn't. With the air conditioning off I got the water heater to fire up. After about 4-5 minutes I had proper draft. That was until I had my wife start the exhaust fan in the kitchen. It immediately snuffed the flame. When I tried the sequence above but with a window open, the up draft was ok. So I'm thinking that the radon mitigation system is helping to create a negative air pressure in the house. Long story, but my question is can a standard gas water heater be converted to a direct vent or power vent system? I just hate to replace a one year old heater.

You can't convert to direct vent. Either seal the water heater in a closet that's vented to the exterior or replace the water heater.

Scooter man, go down to HD and buy a 40 gallon power vented water heater an have a Licensed Plumber install it...vent it rite out the side of the building w/2" Pvc and be done with it. Don't I repeat Don't let anyone talk you into a after market vent kit....they stink and you will have problems like there's no tomorrow.

tjernlund makes an add on power vent.
[www.tjernlund.com]

it is quite complicated, expensive and difficult to install.

I would guess you have a newer, air tight house. Your present heater should work if you provide combustion air for the heater. Older houses didn't have this issue since they were so "leaky", air wise. If the furnace room is that air tight, if you provide a way for outside air to enter, the issue would probably go away.

bruce is 100% correct.
make-up air is essential to SAFE gas combustion.
when gas burns it creates CO2. this is a perfectly good byproduct.
it is expelled up the chimney and into the atmosphere.
BUT, BUT, BUT..
if the CO2 is not expelled to the atmosphere but sucked back into the combustion chamber then you have a disastrous situation.
the CO2 gets re-burned and chemically drops the 2 to become CO. carbon monoxide is odorless and 100% deadly and will kill you.
so at very least open a window to get air into that room. then figure out how to get an adequate fresh air supply inside.
its also a good idea to install a CO detector in the area of the water heater.

yes, it 'can' be converted

BUT

it would be more cost effective to simply replace the heater

OR

provide adequate 'make-up' air for combustion



you will need a fixed OPEN intake 'grill/louver' in the 'furnace room' or basement - preferably low and near the heater - a 3-4" round opening will suffice

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

code requires more than you recommend.
"According to the International Fuel Gas Code, Section 304, each boiler room should have two openings, one within a foot of the floor and one within a foot of the ceiling. This is to allow natural ventilation inside the boiler room. The dual openings also limit the possibility of a single opening being blocked and starving the boiler or water heater for air."..


"

" Vertical opening. One-inch free area for each 4,000 Btu/hr. input of gas burning appliances in the room.

Horizontal duct opening. One-inch free area for each 2,000 Btu/hr. input of gas burning appliances in the room.

Mechanical fan. One CFM of air for each 2,400 Btu/hr. input of gas burning appliances in the room.

Indoor air. 50 cu. ft. of area for each 1,000 Btu/hr. of the appliances."

here they want a minimun of two 10 x 10 grills. one up high and one down low.

absolutely correct

BUT

a 4" will work and 'may' be acceptable within the 'private home' exemption

OR

freeze out the room during a cold spell

OR

avoid the issue and replace the heater

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

ps. @ packy

Quote

.....Indoor air. 50 cu. ft. of area for each 1,000 Btu/hr. of the appliances."

the 'reference' to the (antiquated but still present) exemption granted when residential homes were drafty

so, if the OP installs a smaller than ideal OA intake ................. ?

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

i have seen things like this used for fresh air intakes.
outside air drawn into 5 gallon bucket where it is tempered slightly to not be so cold.
the outlet hose from the bucket is not connected to anything. it just lays there.

never seen THAT before

it all depends on WHERE the OP's heater is located

if near an exterior wall there are many options


What is a fresh air intake?


A fresh air intake is exactly what it sounds like, a path for your home to take in fresh air from the outside. In many homes the fresh air intake is simply an open duct ran from an outside vent into a basement, or any room housing the home’s furnace and/or water heater. Fresh air intakes can be in multiple locations throughout your home, especially in newer homes built to modern building codes requiring homes to be much tighter than older homes.



Homes are built “tighter” to decrease the air lost from the building in order to create energy efficient structures in hopes that we can slowly decrease the stress on our aging power grid and conserve energy resources. The tighter design is also required because of the health implications of air pollutants that are drawn into older homes from attics, basements, and crawl spaces.


The 'principle' whether for a water heater or (as pictured) a furnace:

(damper is optional and practical for furnace only)

I think that bucket looks like a lint trap.

that one is a lint trap
it is the only picture i could find.
the idea is that cold air is drawn into the bucket where it is tempered slightly by the cellar air.

packy,

actually not a bad concept

picture this

55 gallon drum

air inlet using an internal 'dip tube'

air outlet on side near top with EXTERNAL tube ending near burner


when burner ON it will draw air

when burner OFF volume will 'temper' any draft(s)


you hit the nail with this one




==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Thanks for all the ideas and guidance regarding this issue. The water heater is in the basement, which is finished but the room has a full louvered door on it. I think the best solution for me is to replace the water heater with a new HE one that is directly vented.
Thanks again



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