House water heater

Pirate Lady

Pirate Lady

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Jun 2, 2020
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Chesapeake Bay, Middle River
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Sundancer 250 ‘91
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7.4 Bravo 1
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Any water heater tradesmen out there?
i have gas water heater. Most have a vent pipe goes vertically thru the roof.
i have a floor above (split level) so on top of mine is a contraption with a fan that blows it out side of house. This fan has to start before the heater comes on.
many times I have to flip the reset switch on side of vent fan to get it to come on. Happening more often lately.
before I call a fixer, looking for idea what something like this might cost to fix.
Before you say new water heater, that works fine. Some sensor or relay is keeping the vent fan from starting which keeps the heater from starting.
PS I looked at solutions online but it’s way above my skill level.
 
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How old is your water heater? So usually a water heater only last 10 years... And though your Home insurance policy its only Insured for the first 8/10 years of its life... So if it floods your basement it won't be coved... The Hole unit is about 1,500/2,000 to replace... You can also put in a tankless for about the same price I believe... But look into that...
 
If you have a set of schematics, post it and I can point you in the right direction.
Or make/model and I may be able to look it up.
 
When my power vent went out I found it's easier to replace the whole dang thing than to deal with replacing that blower.

It's not the most complicated DIY. A couple hour job. I think my 50gallon was $1100 +/- from Home Depot, with the new vent included...
 
Interesting, I too have a gas water heater but I don't have the blower, just a vented pipe going to the chimney flue.
 
There is a small rubber hose connected to a vacuum type switch. The blower turns on first, which causes that switch to close, which tells the control board that the fan is working. Then the gas valve opens and heats the water.

If its been fine for years, chances are the power vent contraption needs replaced. Its a fine line between it working and failing.

You can try a new vacuum switch, then a new fan, and at that point its the whole unit.

There is a chance that the output vent (to the roof) could be slightly clogged, but I doubt it - given your reset approach is working.

I would suggest an entirely new power vent unit. Easy to replace, probably hard to find the right part number.

Been through this with our house, and it always seemed to give us grief during the colder months. In the summer it worked fine. Perhaps something to do with density of air at different temperatures. I even reworked the entire exhaust trying to reduce resistance with no avail. Finally just replaced the entire power vent and its been fine since. Thus my comment about it being a fine line between working and failing.

Good luck!
 
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It’s most likely a dirty flame sensor. Pull it out and clean it with steel wool. It will be at the bottom of the water heater near the igniter. So here’s how you determine if it’s a dirty flame sensor. After you reset your water heater watch your igniter at the bottom. After it ignites the flame if the flame kick out a second or 2 after it’s ignited it’s definitely a dirty flame sensor. The water heater will attempt to fire 3 times before it locks out. Flame sensors can work very erratically and get worse over time as they get dirty. Oh by the way I’ve been working in the hvac/plumbing industry for over 30 years.
 
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@markrsimon mentioned where I'd go first. A lot of times, that diaphragm switch is connected with a short length of rubber vacuum hose. Check to see that it isn't coming apart.
However, I'm with @Maggieiscrazy on the flame sensor. I have to clean the one on my home furnace pretty much every fall.
 
Pirate Lady said:
This fan has to start before the heater comes on.
many times I have to flip the reset switch on side of vent fan to get it to come on. Happening more often lately.
Click to expand...

Guys, he says he has to hit the reset switch to get the "fan" to come on... Not being able to look at it, it sounds like the blower is shot. Drawing too much current and tripping the breaker switch.
 
SKybolt said:
Guys, he says he has to hit the reset switch to get the "fan" to come on... Not being able to look at it, it sounds like the blower is shot. Drawing too much current and tripping the breaker switch.
Click to expand...
As I previously said. The water heater will attempt to ignite 3 times. Then it will go into a lockout. Hitting the reset switch will rest the water heater and make it attempt to ignite 3 times again.
 
mrsrobinson said:
Interesting, I too have a gas water heater but I don't have the blower, just a vented pipe going to the chimney flue.
Click to expand...
mrsrobinson said:
Interesting, I too have a gas water heater but I don't have the blower, just a vented pipe going to the chimney flue.
Click to expand...
Very helpful post. I used to have two goats, one that liked to eat bananas.
 
markrsimon said:
There is a small rubber hose connected to a vacuum type switch. The blower turns on first, which causes that switch to close, which tells the control board that the fan is working. Then the gas valve opens and heats the water.

If its been fine for years, chances are the power vent contraption needs replaced. Its a fine line between it working and failing.

You can try a new vacuum switch, then a new fan, and at that point its the whole unit.

There is a chance that the output vent (to the roof) could be slightly clogged, but I doubt it - given your reset approach is working.

I would suggest an entirely new power vent unit. Easy to replace, probably hard to find the right part number.

Been through this with our house, and it always seemed to give us grief during the colder months. In the summer it worked fine. Perhaps something to do with density of air at different temperatures. I even reworked the entire exhaust trying to reduce resistance with no avail. Finally just replaced the entire power vent and its been fine since. Thus my comment about it being a fine line between working and failing.

Good luck!
Click to expand...
What you said about cold months is same here. This can go weeks to a couple months in summer but in cold winter I have to reset a couple times a week.
That tells me the whole blower unit is not shot. I may just put up with inconvenience for another couple months, get thru summer fine then fix before next winter.
I do appreciate all the suggestions.
I like the rabbit, daughter had a pet once. Superman.
PSS. Y’all crack me up.
 
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