Kevin Tennant
New Member
This write up is for those that have a little experience with high efficiency WH (Water Heaters) and what to do with icing issues that occur when it's winter, since it's very common, I wanted say something.
If you know what to do, then don't read this and waste 5 minutes of your life that you won't get back as some have suggested, fair warning.
As the title says, there is a common issue with High Efficiency WH that I think is happening to the common fellow. I want to help out and give some advice.
First, if you are having issues with your WH right now, don’t panic. Most WH new and old do have a diagnostic module on the regulator and will frequently have codes flash when there is an issue. So the first thing to do is to read the code.
For those of you that are new to this appliance. You may need to determine what type of WH it is. The older mid-efficiency WH had a metal flue on the top. (hot gas exhaust type). If this is the case, then possibly just relighting the pilot light may fix the issue. Just read the tanks instruction on relighting which is normally listed on the regulator or the side of the tank. I had a mid-efficiency water heater that cracked and was dripping water on the pilot light. Sometimes high winds can blow out the pilot light. Even condensation can drip down onto the pilot light. These issues had happened to me over the years.
For those that have a High Efficiency WH, then you will see usually two PVC pipes on the top. One is exhaust and one is intake. This is a closed loop system. Direct vent is the common name for it. The reason it’s closed is that homes today are built fairly air tight and to prevent depressurization the system are isolated from the house air. This also keeps CO gases from being pulled into the house system as well due to depressurization from other exhaust fans in the house. If you have a High Efficiency WH, then most likely you have a High Efficiency Furnace as well.
One of the most common issue with High Efficiency appliances is the icing or frost buildup on the intake or exhaust of the appliance. The construction industry is doing little to fix the issue and I am seeing lots of ice and frost buildup on houses during these colder days. Typically around -20 deg. C and below.
If you read your WH diagnostic readout, it may say something along the lines of “pressure differential”.
Go outside and see if there is any icing or frost issues. Sometimes it’s not obvious. My clog was up inside the goose neck and it felt like packed snow.
I would recommend using a heat source to melt the ice or frost.
** I am going to suggest something that is not going to be approved by a plumber or repair person**
You may want to remove the intake pipe off the WH and allow the inside air to be used. Again, this allows the air from the house to be drawn into the WH instead of the outside air. This is not going to cause any major issues. Nothing is going to explode or cause injury. It will however cause your WH to get the air it needs to start working again.
I would suggest keeping it disconnected as the ice will build up again. Wait till it's warmer outside and reconnect it unless you are confident it will not ice up again.
The main issue here is that the exhaust and intake are separated based on the Plumbing code. This separation, including distances from windows and openings is there to prevent CO from entering the building. Unfortunately the distance does not take into account the condensation that comes from the exhaust on a winter’s day. I swear these units were not invented in Canada.
One question on another blog asked why they were affected but not the neighbour? it depends on several factors. These include, location to wind, side of house they are located on (south is warmer), location based on other obstacles such as other walls or items such as decks and the temperature of the day.
As a DIYer, you could add more PVC pipe to the exhaust getting if further away from the intake. But just be aware that the manufacturer of the appliance has specific lengths of pipe allowed. The sensors on the WH may be triggered by too long a pipe.
The other question posed in another blog was; why does the furnace not have the same issues?
The main reason is the type of system it uses. The Furnace (or at least mine) does not have a sealed system, so a lot of air comes from the basement through the cracks of the unit. In contrast, the WH is sealed. It has the same system but because there is little air coming from the basement the intake is much stronger of a vacuum to the outside air.
The only issue I have with my furnace is the ice buildup below the exhaust.
Like I said earlier. Removing the intake pipe off the WH and allowing the air in the basement to be used is going to be frowned upon. Every Plumbing inspector and installer is going to protest, but hey, they aren’t at home with a dead WH and a nice cold shower in the morning.
I recommend you get it attached as soon as possible if disconnecting did nothing, then call the professionals as soon as you can. Give them the code you read off the WH too, this will allow them to prepare with parts and such. Less time wasting.
Here is something interesting too that I found out. My wife had read the emergency numbers on the furnace that was placed by the builder (Genesis). It read that hot water tank troubles are NOT considered an emergency!!
Checking the piping for ice/frost will most likely fix the issue for sure and it takes 10 minutes to do so.
If you know what to do, then don't read this and waste 5 minutes of your life that you won't get back as some have suggested, fair warning.
As the title says, there is a common issue with High Efficiency WH that I think is happening to the common fellow. I want to help out and give some advice.
First, if you are having issues with your WH right now, don’t panic. Most WH new and old do have a diagnostic module on the regulator and will frequently have codes flash when there is an issue. So the first thing to do is to read the code.
For those of you that are new to this appliance. You may need to determine what type of WH it is. The older mid-efficiency WH had a metal flue on the top. (hot gas exhaust type). If this is the case, then possibly just relighting the pilot light may fix the issue. Just read the tanks instruction on relighting which is normally listed on the regulator or the side of the tank. I had a mid-efficiency water heater that cracked and was dripping water on the pilot light. Sometimes high winds can blow out the pilot light. Even condensation can drip down onto the pilot light. These issues had happened to me over the years.
For those that have a High Efficiency WH, then you will see usually two PVC pipes on the top. One is exhaust and one is intake. This is a closed loop system. Direct vent is the common name for it. The reason it’s closed is that homes today are built fairly air tight and to prevent depressurization the system are isolated from the house air. This also keeps CO gases from being pulled into the house system as well due to depressurization from other exhaust fans in the house. If you have a High Efficiency WH, then most likely you have a High Efficiency Furnace as well.
One of the most common issue with High Efficiency appliances is the icing or frost buildup on the intake or exhaust of the appliance. The construction industry is doing little to fix the issue and I am seeing lots of ice and frost buildup on houses during these colder days. Typically around -20 deg. C and below.
If you read your WH diagnostic readout, it may say something along the lines of “pressure differential”.
Go outside and see if there is any icing or frost issues. Sometimes it’s not obvious. My clog was up inside the goose neck and it felt like packed snow.
I would recommend using a heat source to melt the ice or frost.
** I am going to suggest something that is not going to be approved by a plumber or repair person**
You may want to remove the intake pipe off the WH and allow the inside air to be used. Again, this allows the air from the house to be drawn into the WH instead of the outside air. This is not going to cause any major issues. Nothing is going to explode or cause injury. It will however cause your WH to get the air it needs to start working again.
I would suggest keeping it disconnected as the ice will build up again. Wait till it's warmer outside and reconnect it unless you are confident it will not ice up again.
The main issue here is that the exhaust and intake are separated based on the Plumbing code. This separation, including distances from windows and openings is there to prevent CO from entering the building. Unfortunately the distance does not take into account the condensation that comes from the exhaust on a winter’s day. I swear these units were not invented in Canada.
One question on another blog asked why they were affected but not the neighbour? it depends on several factors. These include, location to wind, side of house they are located on (south is warmer), location based on other obstacles such as other walls or items such as decks and the temperature of the day.
As a DIYer, you could add more PVC pipe to the exhaust getting if further away from the intake. But just be aware that the manufacturer of the appliance has specific lengths of pipe allowed. The sensors on the WH may be triggered by too long a pipe.
The other question posed in another blog was; why does the furnace not have the same issues?
The main reason is the type of system it uses. The Furnace (or at least mine) does not have a sealed system, so a lot of air comes from the basement through the cracks of the unit. In contrast, the WH is sealed. It has the same system but because there is little air coming from the basement the intake is much stronger of a vacuum to the outside air.
The only issue I have with my furnace is the ice buildup below the exhaust.
Like I said earlier. Removing the intake pipe off the WH and allowing the air in the basement to be used is going to be frowned upon. Every Plumbing inspector and installer is going to protest, but hey, they aren’t at home with a dead WH and a nice cold shower in the morning.
I recommend you get it attached as soon as possible if disconnecting did nothing, then call the professionals as soon as you can. Give them the code you read off the WH too, this will allow them to prepare with parts and such. Less time wasting.
Here is something interesting too that I found out. My wife had read the emergency numbers on the furnace that was placed by the builder (Genesis). It read that hot water tank troubles are NOT considered an emergency!!
Checking the piping for ice/frost will most likely fix the issue for sure and it takes 10 minutes to do so.
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