March 815 pump

Has anyone used the new March 815 pump? It’s supposed to be higher flow than the original 809 and is only a little more expensive so I was thinking of buying it. I just wanted to make sure there were no complaints…


I was looking into this pump, it hasn’t been on the market long but the increased flow is supposed to reduce the possibility of priming problems and the flow is higher. In fact a lot of people are buying the impeller to upgrade their 809’s. So I’d say it is the one to buy.

I bought one recently, but it’s my first pump so can’t compare it to the 809. The flow rate is solid and I’ve had no problems with it so far.

I’ve heard very good feedback on everyones experiences with the 815.

I installed the 815 impeller into my 809 thereby making it a 815. Total flow at zero head is only 7 GPM as compared to 6 GPM on the 809. Where the real difference lies is in the head pressure. Since the impeller is larger in diameter, it makes more pressure by the square of the impeller diameter. This is very important for me because I am pumping 20+ gallons of wort through two CFC’s and I have more syste restriction. So if your system had 10 feet of head restriction you would be pumping at a flow rate of 2.5 GPM on the 809 and 5 GPM on the 815. This is best understood when looking at the two performance curves superimposed upon each other. See below.

Greg you need two CFCs to chill to temp? One with tap water and one with ice?

Interestng that the flow is better through a restriction, that is a distinct advantage.

I’m pleased with the move to an 815 impeller in my old 809HS pump. I never had a discharge problem with the 809 impeller. And that was with pumping through a Therminator and 25 ft of 3/8" vinyl tube, and up 5 feet into the fermenter. Now with the 815, the flow is stronger. That is in agreement with the pump curves shown above. The thing that appears to be the real benefit is the improved ability to clear air from the pump volute.

Definitely get the 815 pump. If you have the 809HS, do consider upgrading to the 815 impeller. That is especially true if you have low flow performance or tend to get air in your pump.

[quote=“tom sawyer”]Greg you need two CFCs to chill to temp? One with tap water and one with ice?

Interestng that the flow is better through a restriction, that is a distinct advantage.[/quote]Only in the summer. I run tap water to both and run the wort full flow in an effort to chill as fast as possible.

I tried shopping for an 815 head to no avail. My search skills must lack. Where did you folks shop?

You don’t buy a head, you just buy the impeller. I think the head is the same as the 809.

I bought the impeller kit on eBay with a thrust washer and a gasket for about $24

Thanks for the knowledge gentlemen.

Thanks to all. As a follow on, I’ve seen most pictures of pumps with the output on top. Since the common issue with these is starting, wouldn’t it be better with the INPUT on top? It would seem to me that would prevent the pump from having to draw wort up at any time… Thoughts?

I am a pump engineer. You need to fill from the bottom so the air can vent out the discharge.

Got ya, problems otherwise huh? What would happen?

Pump fails to prime and pulls a little vacuum, which makes the hot liquid boil and the pump then cavitates.

I ended up getting the 815 impeller, and it moves liquid faster for sure. The difference in impellor size is pretty dramatic.

Chilling took less time, and I watched fermenters fill up much faster than standard. I’m not sure the upgrade is necessary, but it did improve performance.