Do you have a thermal expansion tank on your water heater?

[newbury]

Thanks TBN'rs.
First of all thanks for sticking to the topic for a full 19 replies.
Second for adding to my knowledge base.
Now I'll go back to worrying about anode replacement.

 

[4570Man]

It’s code in my area to use them. My house was built slightly before code enforcement started. I didn’t use one to start with and it was a daily occurrence for the water heater thermal valve to puke a little water. I added an expansion tank and there was no more problem. I expect the millions of people that get by without one either don’t have a back flow valve at the city connection or it leaks a little bit. It’s simple physics that you can’t heat water in a sealed system without the pressure significantly increasing or venting it.

 

[grsthegreat]

Those tanks also stop water hammer.

i replace my anode rods every 3-4 years. The price of the anode doubled since the ones i purchased 3 years ago. Due to magnesium prices.

 

[Streetcar]

tanks have been code in my area for at least twenty years. I did not put one in when I replaced my water heater. I have seen several tanks rusted and leaking

 

[bigtiller]

I have one, I think it is about a 3 ? gallon size. When the house was new, it had a horrible hammering problem. It looks a lot like this one..

https://d3t0tbmlie281e.cloudfront.net/igi/hotwateruniversity/2tetnUPqW5iIhLO4.medium

 

[lman]

It’s code in my area to use them. My house was built slightly before code enforcement started. I didn’t use one to start with and it was a daily occurrence for the water heater thermal valve to puke a little water. I added an expansion tank and there was no more problem. I expect the millions of people that get by without one either don’t have a back flow valve at the city connection or it leaks a little bit. It’s simple physics that you can’t heat water in a sealed system without the pressure significantly increasing or venting it.

I don't have a city connection. I don't live in the city, I have a well.

 

[4570Man]

I don't have a city connection. I don't live in the city, I have a well.

If you have a well you already have an expansion tank.

 

[kenmbz]

I have three expansion tanks on my system.

One for the Oil burner fill at low pressure, so when the boiler side needs water it overcomes the fill valve. Tucked back behind the burner and grey.

One on the system fill (solar storage and hot water storage) which is 50PSI (light beige)

One on the Solar pump which is a limiter to keep pressure below 20 when it's pumping glycol through the panels. Small grey one

Tried to get all three in the picture. I am on well water and that tank is in another area.

The old solar expansion tank and old fill expansion tank lasted many decades. The one on the old oil burner outlasted the burner itself, so about 30 years!

 

[laurencen]

its not code here but I did install one several years ago, the issue was if the water heater has cooled down such as grandkids filling the paddling pools when the boiler cuts in the expansion in the tank and house plumbing was blowing seals on the water softener neck, with the expansion tank its all good

 

[ponytug]

I wonder if there is some confusion about how an expansion tank works? Mine has a rubber bladder inside a metal tank. Not sure how it can rust out? But I only have 5 years of ownership to go by.

I highly highly recommend powered / electronic anodes. We would go through a magnesium anode in six months or an aluminum one in 12-18 months. I got tired of wrestling breaker bars in cramped spaces, plus the first water heater rusted through despite the anodes. The electronic one has lasted over twelve years.

We have a ceria coated one, IIRC, but there are also titanium versions. Longer is better. "Cerro-protect"

All the best,

Peter