Power Direct Vent and Freezing Air

[Alex Collins]

So, the code blinks 7 and a pause (vapor sensor) but its not the sensor.
Only happens when 20F or colder, wind is not an issue.
The intake and exhaust vents are not iced, so its not blockage.
I think it is the Temp Sensor in the blower because the housing is very cold to the touch.
My HVAC buddies are saying the temp sensor would never open due to cold temperatures just 155F and above.
So, something to do with freezing air and it codes the vapor sensor.
I know about concentric kits but I dont want to put that on.

 

[Jeff Handy]

Your post is mostly gibberish.

Are you talking about a furnace, water heater, boiler?

What brand, what model?

Give info off the labels on the appliance.

And post some pictures.

 

[Diehard]

Clue: This is the water heater section.

 

[Alex Collins]

Bradford White RG2PDV50H6N 50 Gallon, Power Direct Vent Water Heater, Natural Gas

 

[Jeff Handy]

Thanks Diehard.
Hard to read that tiny blue print on my phone.

 

[Jeff Handy]

The vapor sensor can also sometimes falsely trip from condensation or other moisture.

Or obviously can trip from small gas leak, paint or solvent fumes, some cleaning chemical fumes.

Sometimes if intake and exhaust are not properly positioned outside, exhaust gets pulled into the intake and causes error codes or shutdowns.
From not enough spacing between them, and exhaust should be higher, intake should be lower, pulling fresh air.
Or at least elbowed away from each other.

I have found water heater and furnace pvc intake/exhaust set up just the opposite, where the exhaust is getting pulled right back into the intake.

 

[Alex Collins]

Th

The vapor sensor can also sometimes falsely trip from condensation or other moisture.

Or obviously can trip from small gas leak, paint or solvent fumes, some cleaning chemical fumes.

Sometimes if intake and exhaust are not properly positioned outside, exhaust gets pulled into the intake and causes error codes or shutdowns.
From not enough spacing between them, and exhaust should be higher, intake should be lower, pulling fresh air.
Or at least elbowed away from each other.

I have found water heater and furnace heaters set up just the opposite, where the exhaust is getting pulled right back into the intake.

This helps me so much, thanks, Now that solves the error code problem. And recently I put on an extension to the intake vent that drops it 8 inches. Is there anything I can do about the freezing air that enters the blower because something is being affected by the cold temperature. Do you think there could be a possibility that the cold air mixes with the heat of the blower housing and creates condensation on the sensors wire connections?

 

[Jeff Handy]

It is designed to run on cold outside air or warm outside air.

Make sure you are not storing any paint cans or anything else with fumes nearby.

A faint gas leak could still be the problem.
Colder air sinks, and on colder days the gas leak or other fumes could be hanging down near the floor, where the sensor is.
Older gas line shutoff valves often have a constant slight leak, try sniffing near them and all around the gas supply lines.
And near other gas appliances, like a furnace or gas dryer nearby.

And on colder days, cool moist air will pool along the floor.
Moisture can fool the sensor into fault mode.

You may as well just buy and install a new sensor, that might fix your problem.
Amazon or many other sources have them for approx $50.00.
If this does not fix your problem, you will at least have a good spare sensor on hand for when you need it in a pinch.

Here is a video that shows the easy swap out of the vapor sensor.
Not the best camera work, but it is quick and shows the easy process.

 

[Jeff Handy]

You might want to call your gas utility, most of them will come out for free with a gas sniffer to see if they can find a leak.

Although a good nose can sometimes be better than these sniffer tools.
You can tell from my profile pic, that I have a pretty powerful sniffer, haha.
I have located some gas leaks that the sniffer tools could not find.

These vapor sensors can be a PITA, but they can save lives.

A friend of my brother was badly burned as a kid, his dad was varnishing furniture in the basement.
The kid opened the basement door, and a wall of flames shot up the stairs and burned him.
His dad was hardly burned at all.
The kid had severe facial, neck, and some hand burns.