What is this?

I have been in the construction industry, remodelling and home inspections for nearly 50 years. I have never seen this before. House was built in the 1930’s maybe early '40’s and I pride myself on heritage homes but this one has me stumped!

My first thought was an older hot water system, but there is no evidence of any pipes or rads now or previously in the home. To day it is forced air natural gas.

I know someone out there has the answer? Much appreciated in advance.

Short answer for Backflow Prevention.


So, from the picture, looks like it is protecting the (old) garden hose water from backflowing back into the main water supply.


Common as flies around here on every in ground sprinkler system.


Not many flies as yet as it too cold, but no inground sprinkler system either… Will go by tomorrow PM and take a further look. System looks old and is disconnected but another look will not hurt.

Sure looks like there is.

Look harder.

Sometimes there is no controller just a set of manual or unwired zone valves in the yard somewhere.

Like this one from a couple of weeks ago.

No controller just zone valves next to a bush in the yard.

Sure looks like the same animal to me Mike.
Good identification.

Very common here in AZ

Why do you need them in Az you have no water:p;-)

We send way to much to southern CA. That’s why most sprinkler systems here are a drip. Costs too much to water grass here when it is 115 outside

They are not popular here as they need to be flushed out every fall and in commercial applications you will not see any of that are outside but in the utility room.
I have seen 2 in 5 years outside.

They are required Here for outside irrigation…there is one quite like that on the front of my house…

KW there are a lot of things you have not seen at age 49 its code here, they are a must between city water and a sprinkler system:roll: and anyone with any common sense knows they are winterized before cold weather sets in for the winter and that takes care of the flushing???

Charley there allot of things you have not seen. Each area is different. I don’t see these because of the extreme temperatures not because of my age. Things you probably have not seen is new materials and technology.

I don’t know everything never claimed I did but you sure have your nose in every thread as if you know it all. I have forgotten more than you will ever know;-)

Charley I take in every information I can daily and the least from this MB but on occasion can’t just sit back and wait for the right answer here.

Maybe you could try providing the right answer.

AND admitting when you are wrong.

Sorry Kw if you live to be 105 you will never encounter the experience that I have lived. I worked in the real world I was not a janitor:roll:

Yes I have because before during and after I was working. I started out as a masons helper at age of 14. I took huge contracts in Custodial during the winter time because there is no environmental work or very few HI’s in the winter.