Where to add zone valves to existing system.

[BobbyDIY94]

I currently have a boiler with only one zone of heating that is a 1 1/4” mono-flow system. The pump is on the return side near the boiler. The expansion tank and makeup is on the supply side near the boiler. I want to add two more zones for a new total of 3. The two new zones will have 1 inch supply/return manifolds located 5 feet from the boiler. I plan on getting 3 taco sentry valves and the taco zone board.

1. What side should the zone valves go on in my set up, supply? return?
2. What size piping should go to the new zone manifolds. (Plan is to do 1-1/4” tee off the existing system with a short length of 1-1/4” pipe leading to a 1-1/4” x 3/4” x 3/4” tee, With the 3/4 “ lines going to the new manifolds.)


Thanks for the help!


Also, the existing system will have half the radiators removed so there will be much less heating demand on the 1- 1/4” piping.

 

[Fitter30]

Right side of boiler towards the back towards the bottom looks like a 1" line to ?
Have relief valve problems or boiler pressure rises when on more than a few lbs?

 

[Sponsor]

 

[BobbyDIY94]

Right side of boiler towards the back towards the bottom looks like a 1" line to ?
Have relief valve problems or boiler pressure rises when on more than a few lbs?

Return and supply are 1-1/4”. Unsure of what you’re asking?

Thanks

 

[Reach4]

I think he is asking if you release water due to the water pressure rising to the pressure of the relief valve, and then get makeup water added when the water cools. That could be caused by an undersized thermal expansion tank, a defective tank, or not having the air precharge set properly. I may be off base on that.

Turning off the makeup water could help diagnose.

 

[Fitter30]

Return and supply are 1-1/4”. Unsure of what you’re asking?

Thanks

Right side towards the rear of boiler there is a copper pipe running next to the boiler. Wonder if you have had problem with boiler pressure?

 

[John Gayewski]

The pipe size is based on the load. How much heat do you want. Zone valves go on the supply side.

You should change some stuff about your boiler piping if your already cutting into it.

 

[Fitter30]

Mf systems are design with a particular pressure drop. What type of heat emitters do u have? Are there shut off valves on each emitter? What are the pipe sizes? Do u have boiler reset control it vary water temp by outdoor temp.
They make thermostatic radiator valves or motorized ball valves that might work.