Print

[lmann]

It's a 007 pushing 3 runs of 300' of 1/2". Is the pump large enough? Is it plumb right? Should I change anything? I'm thinking about adding a fan backed w/a for faster recovery. How and where in line should I add it?

[slimjim]

Do you have another circ at the wood boiler or is the little Taco pulling through both valves, if it were me I would make the wood boiler loop a Primary loop that runs constant, without the diverter valve and control the floor temps with the Taco in the picture, it appears to me the Taco is pulling a very small amount of water through 2 mixing valves

[lmann]

There is a 007 at the boiler running constant to the building.

The black valve is the central boiler thermostatic valve that is needed for their warranty.

Above that is the mixing valve to cool the temp before it is pumped into the floor when calling for heat that pump turns on.

[lmann]

Here is a diagram of the garage plumbing from the boiler.

Boiler with 007 pushing the 40' of 1" thermo pex to the garage.
All other plumbing is mounted in a 4'x4' area.

Do I need a larger pump pushing the floor? I've tried in temps of 110-140 but I only get 80 coming out if the floor.
The floor is 3 runs of 300' of 1/2". One zone.

Is this plumbed right?
What's correct?
What's wrong?

[slimjim]

300 feet is in my opinion stretching it but also keep in mind that it may take days before the floor is up to temp and only then will your return temps stabilize.

[lmann]

300 is stretching it. For the pump? Or for design? I read to keep the runs 300 or under. So I put three runs in the 30x30 slab to keep them under 300 each. I started the floor heat early this year before it got cold to try and stay ahead of it but didn't seem to make much difference.


I've been fighting with this boiler and design for house and garage for 3 seasons. If I can get 6-8 hours of burn time it's a miracle.

I'd like to get to where I can brag about how great wood boilers are.

[slimjim]

300 feet is a long run in my opinion per loop, all three loops are off the same circ am I right?  One place that is very important and often neglected is perimeter wall or edge of slab insolation, some estimates are that up to 80% of lost heat lost from radiant in slab is around perimeter walls, could this possibly be your problem?

[lmann]

Yes. The 007 is pushing the manifold that has the three 300' runs of 1/2".

I have 2" pink foam under slab and 1/2" around the sides (the thickest without being wider the the siding)

Each of the three runs starts toward an outer wall as to put the most heat there when starting.

I'm thinking I need a bigger pump (0011) to push the water thru the 3 runs of 1/2" (300' each) in the floor.

[slimjim]

A 00-11 will be to big and will cavitate the circ, could you shoot the floor to see if you have hot,cold spots in it? Any chance the pex got crimped or crushed in the slab? Do you have flow meters on each loop of the manifold? If so what is the GPM and are they balanced? Are you sure you got ALL the air out of the loops?

[lmann]

I ordered a 00R 3 speed pump. Will that be ok?

The floor seems fairly even for temps. I'll double check with my IR temp gun.

No flow meters. They all come off one standard manifold.

I'm pretty confident all the air is out. Is there a preferred method to verify all air is out?

[slimjim]

Remember, water will take the path of least resistance, you must purge air from just one loop at a time, all other loops must be shut off in order to drive air out of the loop you are working on.

[lmann]

I shut down my house loop to bypass the w/w ex for the pool in the off season.
When I closed the house loop I noticed the boiler cycled less. Now I'm thinking my issue might be the house design.

Roughly 290' (included fittings) of 1" pex then the thermostatic valve to a sidearm for w/h and a w/a ex in the furnace.
All originally fed by a 007 at the boiler. I swapped it with the 00R (0015) 3 speed. I've tried all speeds and not much change. There's a 6-8 drop in temp from boiler to house (65') of thermo pex according to the water temp tee I added.
Is the pump still not big enough?

[marty]

It seems like dropping 6-8 degrees with 65' is way too much.  I'm wondering if you are getting bad temp readings. 

[lmann]

I'm thinking I'm not moving the water fast enough.

I bought the temp tee setup because it actually ties into the pex and is in water. Versus reading the pipe temp.
I'm gonna try and use another method (different thermometer) and see what I get.
Some have used wireless meat thermometer. I'll see what the stores have.