Get a no heat call today at this rather large office complex.

Neither floor has heat. First off, owner tried to install new t-stat. Not too successful, rewired t-stat. Now we have heat up stairs.

It's kinda hard to see, but we have 2 radiant baseboard loops on circulators. But in the back we have an injection radiant system. 1 Zone only. It is only 1/2 inch that provides heat for the whole building.

This picture shows us the green Taco (newly replaced) as the injection primary loop and the red grundfoss as the injection loop to the radiant manifold. These are just circulators not injection pumps.

That single circulator runs the whole radiant system. There are 26 radiant loops. They are separated into 4 banks or zones with 6 to 10 loops each. Very long time to heat building, not very effeceint.

This is how *all* the radiant loops are installed.

This is the ARGO panel and radiant mix control.

My questions, is this system correct? Are there things to this system that I can reccomend to help improve it?
Is this the correct use of an injection system? Are the supply and return large enough?
I'm used to seeing a seperate circulator for each zone manifold. Also used to seeing a radiant tank for the whole schebang to give the boiler a break. This poor boiler never shuts off. I was there for an hour after repairing it and it never raised above 130 deg. The stat is set for 190. That brings up the 2 baseboard loops not providing enough for the top floor.

I have a few more pictures if that would help. The boiler and the manifold settings.