Need some help on this one!

Randy-LeeBraman

Got called in on this one,boiler is a Peerless Purefire 110 it is piped P/S 4 zones one is a hydro coil the others are radiant.
All 6 pumps are Taco 007s.was installed 4 years ago.i was called last year because it wasn't heating the house and was costing $1,500 a month in propane.Last year we pulled all the pex loops we could get to down and reinstalled with plates,made a 2 inch air space and reinsulated,this helped greatly.Now its time to attack this boiler pipeingi'm posting
a couple of pics to show it.it seems to me the two pumps in the loop would be fighting each other,one is in the supply and the other in the loop the zone loops are attached to,i have never seen one piped like this.the boiler seems to run a lot modulating up and down.there is a lot of clean up on this one,get pipeing level,electric,etc.any ideas
thanks Randy

SWEI

Randy-LeeBraman said:

Last year we pulled all the pex loops we could get to down and reinstalled with plates,made a 2 inch air space and reinsulated

Plates are good, but why add an air space?

Randy-LeeBraman

This is a old farm house wide board floors,the air space was created by stapling up the reflective bubble rap,which seemed to help a lot .when i first went to look at the system they had the
the lops at 160,doing what i did allowed for the temp to be brought down to 130 and it was still was a great improvement.
My problem now is the pipeing and to see if i can stop this boiler from its erratic cycling .

Ironman

I don't see any pumps "fighting each other" in the pics. The piping is p/s series and all of the loops are injecting into or extracting from the main loop which has its own circ.

Paul48

The primary loop tees are too wide apart.

Randy-LeeBraman

Ironman if you look in the first picture in the lower left corner
you will see a pump in the bottom pipe run,it is pumping toward
the 't' which has the system pump coming from the boiler,so it being piped P/S you have two 007 pumps in the primary,and the
compression tank is totally in the wrong place.

Ironman

I agree that the expansion tank is in the wrong place; or the primary loop pump is, depending which you may want to move. Just for clarity: the primary loop is the loop where the PONPC change is, which is the picture frame loop in your pics. The loop from the boiler is not part of the primary loop, it's a secondary loop just as the zone loops are. Every loop entering through a set of closely spaced Tees is secondary loop.

In this setup, all the secondary loops "see" the primary loop as the PONPC. Therefore, the pumps are not fighting each other.

As Paul pointed out, the spacing between the Tees is too wide, but the pumps are in separate loops.

Paul48

It's hard to tell from the pictures, but the spacing on the tees for the zones may also be too wide.

Randy-LeeBraman

Ironman thank you for the correction.Spent some time yesterday fixing some of the things that i found in need like leveling the pipeing and leveling the boiler which had a forward lean of a
1 3/4.The weight of the pipeing had actually started to crush the one side of the cabinet.
When i go back on monday i'll check the spacing.The more i look at the system i think the major problem might be that it may not be right for the envelope of the building,old farm house looks like mostly plaster and lath walls,don't know if any heatloss study was done.

RobG

The first thing I would do is the heat loss to see if the boiler is sized correctly and if supplementary heat will be needed. The next thing will be to take out the bubble foil and put in fiberglass insulation without an air gap. I hope the homeowner knows that you are trying to repair someone else's problem and it is going to cost them to fix it.

icesailor

On a drawing by a major boiler manufacturer: "No more than 12" apart but as close together as possible".

You're never wrong when the tees are as close together as possible. They must say that for a reason.

Tinman

If it were me, I'd start over. All the "closely spaced tees" look way too far apart for my comfort. Refer to Siggy's book for a good detail of that. At the point where the boiler piping is teed together, it's already P/S so you could drop the supply and returns from the zones into separate headers. And from the pics, it sure doesn't look like you're pumping away. The electric could be cleaned up a lot. Whips that long in the Chicago area wouldn't be allowed. And I agree with SWEI, no need for the air gap between the plates and the insulation. I LOVE cleaning up jobs like that.

Tinman

If I choose to go with many pumps or let the homeowner talk me into it, this is how I keep the electric "clean".