If you are a victim of an ongoing downdraft that causes your water heater or boiler pilot light to go out or the spill switch to trip off due to sudden sporadic downbursts that have no warning. There’s nothing more frustrating than replacing part after part and still not solving the problem. I’ll show you some simple solutions many people don’t even think about. What “solutions” to avoid and why. And what gets to the heart of the problem without high cost.
What is a Downdraft?
A downdraft or downburst can occur at any time, typically during a change in weather when a column of air descends. The downburst enters a chimney through an open, uncapped chimney top. Typically, most chimneys have a rain cap, but there are a lot that don’t, which are susceptible to diverging wind currents. The cap is not what it sounds like. It is a metal-type hood open at all four corners, which allows flue gases to escape and usually prevents downdrafts and precipitation from entering into a chimney.
Here are a couple of rain cap pictures from recent jobs:
If your chimney doesn’t have a rain cap, having one installed would be the first step to direct downward wind currents to another route and stop precipitation from entering your chimney. The sole function of the rain cap is to keep the chimney dry and stop downdrafts.
Do flue liners fix it
Importantly, if an HVAC technician has advised you to have an aluminum or stainless steel flue liner installed, do not, and I repeat, don’t have it installed. A liner will lead to future problems. Most chimneys have a terracotta tube or brick lining. An aluminum liner will not establish a flue draft or keep your chimney warm and dry. Although most technicians and manufacture tech support teams advise a liner installation it’s not the route to take. A rain cap is the correct solution.
A flue liner other than a full inside dimension rebuild will downsize your chimney, and downsizing can lead to severe flue gas buildup in the equipment. The restriction from downsizing from inserting a smaller liner through a properly sized chimney can cause high levels of carbon monoxide to escape into your home. I’ve seen it first hand quite a few times. So before you go ahead with installing a liner think twice about proceeding.
Still have downdrafts?
If after you have a rain cap installed and you still have the problem then a couple things could be the cause. Don’t panic! One problem could be low draft. What I mean is your basement does not have positive air pressure to push the flue gas up the chimney. Two you have a short chimney or it’s on the low side of your roof. Even with a rain cap a chimney can still experience problems.
Below are pictures of a particular short flue case I had and resolved:
Regardless of whether any of these issues are causing you to experience problems with your water heater or boiler sporadically, this is no reason to change the equipment or have a liner installed, so don’t do that.
What stops the downdraft?
In certain circumstances chimney heights and internal building pressures will interfere with the combustion and drafting process of water heaters or boilers. In these particular cases there are solutions to simply fix the problem. The cheapest repair without replacing the equipment unless it’s damaged is a draft inducer.
Here is a video of a recent draft inducer job:
The wasted costs associated from a downdraft or low draft problem is premature equipment replacement or the unnecessary related service calls which usually just waste money and don’t fix the problem. In most cases if a water heater or boiler would carbon up in result of a low draft or downdraft, the boiler would need to be taken a part and cleaned through each cast iron section of the heat exchanger. The cleaning is very costly and has no guarantee of being successful. A water heater on the other hand would require replacement no doubt about it. In hindsight of these two problems if you get involved with a wrong service company that replacement may end up at a high cost to you. Or you may experience the same problem all over again doubling the cost.
Just by having a simple service check of your equipment that includes a draft and combustion analysis test by Vince will identify any potential drafting or combustion related issues which are invisible.
If you want to get the problem fixed right, Schedule a call with Vince for a draft and combustion analysis today.
