Hydronic heating: pump on supply or return

billchat

I replaced my home heating system with a Pex zone system but was wondering current thinking if the Taco pump should be on the supply side or return side. I reused existing cast iron radiators. Also should I have installed ball valves on zone supply and return , before or after individual zone valves.

Paul S_3

Install valves after the zone valves so you can completely isolate the boiler for repair with drainig the entire system....did you install an air eliminator ? Circulator pump should be on the supply pumping away from the expansion tank .....also connect the water feed to the point where the expansion tank connects....also if you can post a few pics of your system....

delta T

As Paul said, pump away from the expansion tank. This is more important than whether the pump is on the supply or return side, but common practice is supply out of boiler to air eliminator/expansion tank/fill connection, then pump away from that.

The more ways to isolate the better (within reason), valves are your friend. Also make sure you can easily purge any part of the system you will need to to eliminate air if you ever have to drain it. Can't tell you how many simple repairs have ended up being much more work simply because I have to add a purge set up to a system that does not have one.

Pictures please, and we can tell you what you need (if anything).

NY_Rob

Speaking of purging, I picked up one of these for my system- specifically designed for purge & fill... should make the job a bit easier.
http://www.supplyhouse.com/Webstone-48613-3-4-IPS-Purge-Fill-Full-Port-Forged-Brass-Ball-Valve

Paul S_3

Webstone makes great products....they have a valve for everything....

unclejohn

Do they have one that stops kids from moving back in?

SWEI

It's an APRP (Anti-Progeny Rehousing Preventer)!