Failed zones

Weezbo

However, i live a ways from you.i am wondering what type of control hydronic and mechanical/electric you may have.

there is some possibility that there is circulation ..it may be that you have "Dummy radiant' off a porportional mechanical three way mixer set at low temp and the water is never going to come out Hot as the system is designed by setpoint ...or it may be the circ or the zone valve controll transformer or a common power wire...as a thought.

layout can certainly make a bad system worse to nonexistent...hard to know without Being There.

john dabbs

Failed zones.

We have a multi-zone underfloor hydronic heating system. We have been experiencing unusually cold temps recently (such that we sustained frozen plumbing pipes). Our heating system worked fine initially but over the last two days two adjacent zones have malfunctioned - no hot water circulating. To the best of my abilities I have established that the zone valves (simple, single throw switches) are working but no hot water is passing thro the zones.

Could the pipes be frozen? Would they not have some glycol component?
Could the internal mechanism on the valve be jammed even though the plunger moves in and out?

Ken_40

Frozen pipes are possible but,

more likely problem is air in the piping.

Take a look at the circultors(s). Is the direction of flow going away from where the expansion tank joins the piping, or the opposite?

If the latter, you need to switch it around. If the installer is still in business, get hime to correct the problem.

It would seem extremely improbable that two zone valves could die at one time, unless a dedicated transformer is shot - that powers them and them only?

Darrell

Yes, your heat tubes could be frozen near an outside wall or corner.

No, there is not necessarily antifreeze in your system, probably most systems do not.

In the two zones affected, measure the floor temperature. I use an infrared heat sensor, you can get one at the hardware store. If the floor temperature is below freezing then that tells the tale.

The fix is straightforward...you have to warm the floor up. You may have to pull carpet up to do that in a timely fashion, and you'll have to move furniture. Remember that carpet is insulation. If you have cold migrating in from an exposed rim, then the carpet insulates the floor and the tubing from the heat of the room. If you find a cold spot in the floor, check outside and insulate the rim...at this point anything will do, sheet foam, sawdust, whatever, until you can dig up the rim and do it right.

There is not likely to be any damage to the tubing.

john dabbs

Your help

Thanks for the thoughts - this does give me some direction. Why do you say it is unlikely the pipes have fractured? Mine, as I recall are Cu with an outside coating in orange. But I hope you are right.

Darrell

By Cu, if you mean copper tubing in the floor, then it may have broken. The piping in the walls or Crawl space to get to the floor is another matter.

If the tubing is plastic, it will usually take a freeze without breaking...the floor may crack.

john dabbs

Zones

Thanks, guys.
Pipes were frozen somewhere - walls, I guess - no breaks and are now thawed. Thanks for the assistance.

Bob Gagnon plumbing and heating

now have someone

Add HYDRONIC anti-freeze to the system, so it dosen't happen again. Bob Gagnon

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