Boiler radiant piping design okay?

josephny

Have I diagrammed this correctly?

The EZ Manifold has plug on the return and an elbow piped in on the feed (both above the valves) -- not sure what goes in these ports.

But the bigger question is whether I'm finally grasping P/S loops and the nuances of which components go where.

Thank you!

Ironman

Unless you have an extremely large house, that boiler will short cycle itself to death and perform poorly while doing it.

I would suggest that you use a properly sized boiler with an indirect water heater. By the time you add a buffer tank to that present configuration, and have to descale the domestic heat exchanger in that combi on a regular basis, you’ll  be worse off than had you done a correctly sized boiler with an indirect.

Youngplumber

Tankless systems, as I have learned here; from Ironman no less, want cold water to return to them.
I'm not a fan of these, or these piping arrangements, but also I don't think your is quite correct in this context. 

Matt_67

That is a combi boiler with minimum fire about 28k - if the manifold can get rid of that much heat short cycling wouldn’t be an issue. It would be good to do the calculations to make sure and if it’s zoned I would be especially diligent about ensuring the load isn’t less then 28k when the smallest zone is calling. I too prefer indirects but the combis have their place. The general order of components in your diagram looks correct.

josephny

Oh no! I didn't realize the minimum fire was 28kbtu. The floor area in zone 1 (the only zone at this time) is approximately 800 sq-ft. At 22-30 BTU/Sq-ft, that's 17,600 - 24,000btu. I plan to add an additional zone, but it will probably be smaller. Am I going to be in trouble? I already bought all the equipment.

Ironman

Why don't you see if it can be returned? Even if you have to pay a restocking fee, you'll be better off with a properly sized boiler and indirect.

If not, you're gonna need a buffer tank.

Is the floor a slab or staple up?

josephny

Staple up.

Thank you.