Radiant heat system question

[JDemaris]

My family and I are presently "house sitting" for part of the winter. The house we-re in is 15 years old and I've got some questions about the heating system. It has a propane fueled boiler. Half the house is on baseboard and the other half has "radiant" heat with plastic pipe in the floors. Some furnace repair guys were here just before we arrived a few weeks ago and supposedly "tuned it up." Well - none of the radiant heat works at all. The baseboard works fine. Since this house is super-insulated - it still stays pretty warm even with only 1/2 the heat working and it being 8-12 degrees F outside.

I'm trying to diagnose best I can and would like a general idea of how this sort of system is supposed to work. I'm not clueless with low-tech heating - but this thing is complicated. There are wires running all over the house and there are no plans or schematics.

The Weil-Mclain boiler makes all the heat and domestic hot water. The baseboard heat works fine but I see no circulator. Maybe hidden somewhere? Doesn't matter I guess.

The radiant system has mostly Wirsbo components. Has a circulator, a relay, and a big manifold with a series of "telestats" or "actuators."

When a thermostat is turned on to make heat - the actuator hooked to it will respond and open. But - the circulator does not come on so there is no heat. I can run a jumper wire across two low voltage terminals on the circulator relay and then the heat works.

So - I'm hoping someone here can tell me generally - how this system is supposed to work. I went to the Wirsbo Website and read a few of their manuals. Problem is - there manuals all show the use of a circuit board called a "Zone Control Module" that acts as an interface between the thermostats and actuators. This house has none. Maybe the older systems did not have them?

I'd like to know what order of things happen when a thermostat calls for heat in this system? It opens an actuator in the hot-water manifold. But - what sends a signal to the circulator? Any help appreciated. I may have to trace every wire and draw a schematic to get an understanding of this mess.

 

[baldwin racing]

the square box with the out let box behind it is a 24 volt transformer....that taking 110 to 24 volt witch is powering the zone valves and the thermastat....hard to tell in pic but it looks like there is only one 15-58 grundfos circulating pump like you mentioned. looks like the pump should be running 24 /7 but im not there to see it....power should run from 24 volt trans to thermostat then to the zone valves....idk if that helps or not?
I guess the plumbers detuned the system not tuned it?
kelly

 

[Nate V. IA]

I would look to see that the circ pump isn't tied to an outside temp sensor. My chicken house is setup so that if its below a certain outside temp the circ. pump just runs continuously. Someone may have that set way to low if you're seeing 8-12 degrees outside. Just an option, I'm a novice at electronics.

Nate

 

[Bonnan]

JD......I would post on either of two sites. Heating Help or GreenBuilding Talk radiant forum.
Those guys are experts and helpful. I designed and built my own but not familiar with your controls.

 

[willie in mn]

If I would be in that situation I would do two things. First report the problem to the owner. Secondly call the people who did the supposed tune up & have them try again, their tune up didn't work.
Willie

 

[MarkB_MI]

I know that with Honeywell valves, the circulator is switched through the zone valve actuators. You have to have at least one zone valve open to turn on the circulator. It appears that when they added the floor heat, they made the bad assumption that at least one baseboard zone would be on anytime the floor heat was on.

See if there's a switch in your valve actuators that hasn't been connected. Those probably need to be connected to the circulator relay, just like the zone valves for the baseboard zones.

 

[JOB]

Willie gave you the best advice. Hot water heat is
not that complicated if you understand the system. I
would not work on someone else's system not knowing
how it works. As Willie said call the owner and let
him call the people who installed the system. You are just the housesitter

 

[JDemaris]

I'm not just the house-sitter. The house is owned by my wife's parents. They can no longer handle the place in the winter. I see them on a daily basis.
We are here to keep the snow plowed and make some repairs on the house while they spend the winter in a condo nearby (northern Michigan). The heating contractor that installed this system is out-of-business. There are no plans or schematics. The people they called to check the system over and "tune it" may of caused the problem it now has. So, none of us are eager to call them back at this point. At least not until we know a little more.

I agree that the system would not seem complicated if I understood it. That pretty much goes with anything. That's why I'm trying to get a general idea on how this thing is supposed to work in theory.

The main issue seems to be the Grundflos circulator not turning on. The relay and 24 volt transformer that is there to power it works fine if I put a jumper wire on the low voltage terminals. I just do not understand what is supposed to do that normally when heat is called for? It's not hooked to any aquastat. The thermostats are hooked to the little actuators. They open OK. I find nothing that is supposed to send a signal to the circulator. I'm wondering if the last "repair guys" that were hear screwed something up and maybe unhooked something? There are a lot of bare, low voltage wires hanging in air and they look as though they were once connected to something.

 

[johnlobb]

I agree, Heatinghelp.com has a "wall" that you can post questions on and experts are very good about helping.

 

[Dusty MI]

I would think that all the zone valves would be wired alike.
Most thermostats when calling for heat open the zone valve, the zone valve has an end switch that closes when the valve is open, that switch turns on the pump. I'd look to see if the end switches, on the ones that the pump does not run, are hooked up like the ones that do. I would think they would be all alike.

 

[Scott 730]

Is there only 1 pump, or do the base board zones have their own pump?

 

[evilboweivel]

1st?? are the actuators two wire or four wire?
1a if four wire then does one set of wires go to a dry contact normally open? then wire all acuator contacts parallel to the relay ofr circulating pump.
1b if two wire then I recomend installing a two pole relay before each acutaor, such that one pole turns acuator on and the second pole turns the ciculating pump on
best bet would be to track down how it is wired OR tear out all control wiring with the esception of t-stat wiring and wire it how you want.

IF you want I will draw control wiring up for you and snail mail it to you. I would need some more info on control wiring for the boiler.

wish you were closer as this would be easy to figure out in person.
email should be open

Good Luck
Ron

 

[JOB]

It would be nice if you gave all the facts first.

 

[M-MAN]

There is a zone control somewhere or they have it all running off the thermostat. Test your thermostat wires and see what's hot when it's calling for heat. My guess is it's going to be wired like a heat pump with one hot to the actuators and 1 that is supposed to go to the circulator relay. I'm guessing a couple of wire nuts came off and were put back on wrong when it was serviced. Shoulden't be too hard to trace the relay wire back to the bundle from the stat once you find the hot to hook it to.

 

[Anonymous-0]

The transformer your looking at usually takes care
of small motor in zone valve and each thermostat.
you have 24 volts going to each zone valve and
then up to thermostat back to transformer. when
t/s calls for heat motor moves in zone valve
closes a normally open switch to closed position.
This switch completes a circuit for another
transformer inside boiler front cover to complete
a circuit. This causes prepurge of gas,circulator,
and gas valve to open and raise boiler temp. to
temp setting set on boiler. If your t/s is
calling for heat and circulator does not go on
your end switches on zone valve have gone bad. you
might not know this because 1 zone valve can work
correctly and have whole system work. Each zone
valve has a thermostat. cast iron radiators water
temp somewhere around 160 degrees. copper fin tube
around 190 degrees. wirsbo tubing I think below
140 degrees. your plastic tubing should have
tempering valve on that system. hope this helps
just my opinion.

 

[JDemaris]

Thanks for the explanation. I got the heat working but in a way that should not be necessary. I don't know if a part went bad or this house was not wired properly to start with?

When we got here we closed off one end of the house since we're not using it. Basically just closed off the "master bedroom" and "master bathroom." That "master bathroom" is part of the radiant heat system. We had it closed off and the thermostat turned down to 60 degrees F.

Ends up that none of radiant heat anywhere in the house will work unless that "master bathroom" has the heat turned up. There are four separate "heat zones" with this radiant system. Master bath, kitchen, living room, and library. Each has their own thermostat. If the master bath is set at 60F, and I turn up any other thermostat in the system - the actuator/telestat hooked to it responds and opens but no water circulates.

So for now - we have that unused "master bath" set at 70F. This way, any other room with radiant heat works fine and heats up to whatever the thermostat is set at. Make NO sense to me but works. I find it hard to believe anybody would purposely design a system like this. My in-laws never noticed since when they live here - the master bath was turned way up all the time anyway.

 

[MarkB_MI]

Not right, but not surprising. It's bad enough that the original installation wasn't done right, but it's equally inexcusable that the guys who installed the upgrade didn't make it right, either.

 

[55joe55]

In my opinion it sounds like a few of the zone valves have gone bad . the end switches go bad all the time. You should have heating contractor come in and check end switches to make sure they all work and change as needed. hope this helps. Been reading site for a few years try to help as needed. thank you. I will always try to help.

 

[Dusty MI]

JD, if you want maybe I could stop sometime and see if we can figure it out. I travel through Northen Michigan some in the summer, so it would be next summer. PM me if you want.

Dusty