New Ecobee3 + New Boiler - Ecobee 3 error message - Room Temp dropped 3 deg despite call for heat

purduealum91

Hello everyone,

First post here. Our new to us home (we are in the northeast) is hot water baseboard heat with two zones (main floor and second floor). We recently installed a new natural gas US Boiler Brand Series 2 (206) boiler and two ecobee3 thermostats. Since install, we have not been able to have both zones above 70 and have received ecobee3 error messages.

For example,

Main floor bee was set to 70 and second floor bee was set to 67. Overnight the main floor bee issued a warning that there may be an issue with the boiler. The temp had dropped more than 3 degrees despite the call for heat. Upon waking, the main floor indoor temp fell to 62 and the second floor indoor temp was stable at 67.

Both zones have been purged of any air in the line.

Can anyone help us?

Thanks,

Tom

purduealum91

I'd also like to add the water temp is at 190 and the water pressure is at 18 psi. The home is a two-story 2,000 sq. ft. Colonial with basement.

Jamie Hall

A Boilermaker, eh? Well, there are a few of us here...

But this one, anyway, needsalot more information to start figuring out what's happening. I presume that water temp is the boiler output temp. In which case, I would expect that the burner is not firing -- it should be off on high limit.

So...

How is this piped? Primary/secondary? I hope... and how is the circulation through the boiler done? Pump model? That circulator should be controlled by the aquastat on the boiler. Then -- how are the zones controlled? Circulator pumps? Or a single pump with zone valves? What should happen is that when a thermostat calls for heat, either that zone's circulator should turn on, or the zone valve should open -- which should turn on a circulator. In the meantime, the boiler should just be chugging along.

It sounds as though something in this control sequence isn't right -- or the actual piping isn't. A piping schematic might help...

cwilliams2000

If it helps, I have a couple of Nest's and one of them has failed 4x all for different reasons. My advice to take the ecobees out of the loop is to go and buy the basic honeywell wall thermostat for about $30 replace the ecobee (one of them at least) temporarily and see what happens. All the tech stuff is great but I heard many complaints about the ecobees and the nests are not without problems also. My last one just died on one of the coldest nights, totally dead. Thought my boiler had failed, nope just my junky nest for the 3rd replacement. Working now but I have absolutely no faith in them, being cold isn't fun especially when 50 year old thermostats worked just fine and pc's don't just blowup after a year anymore, at least not since the 80s. A lot of trouble and you may find out thats all it is. Good luck and be careful.

Jamie Hall

Which is why my backup thermostats are Honeywell T87s with mercury switches... They're bulletproof.

Steve Minnich

I agree. The 206 is a straightforward cast iron boiler. Before replacing the thermostats, jump them out one at a time to see if anything changes. Don't start replacing parts for the sake of replacing parts.

purduealum91

Thanks for all of the replies so far.

There is one Taco brand circulator with two Honeywell Zone Valves.

Stephen, what did you mean by jump them out one at a time? Take them offline?

Steve Minnich

This is where it gets tricky because I don't know your familiarity with these things or your skill set? If you're comfrotable changing a thermostat, you should be comfortable doing this.

Turn off the power at your boiler.

Remove the two wires from one of your thermostats.

Twist them together. Put a small wire nut on them.

Turn the power at the boiler back on.

This will simulate a call for heat for that zone. A continuous call for heat because you have bypassed the thermostat. If that zone valve opens, stays open, and the pump and burner come and stay on until you want to start opening up windows, there's a very, very good chance the problem is the thermostat.

Don't leave it like that.

Abracadabra

I've installed several ecobees. If after jumping the thermostat you find that there's a problem with the thermostats (and not your boiler) I've found ecobee support to be very helpful.

purduealum91

Each ecobee currently has three wires: Rh, W and C. I'm assuming that the C remains unused when I simulate the call for heat (Rh and W twisted together).

Steve Minnich

Correct

hot_rod

If you are wiring thru a relay box, you may need to use all three connections. Nests don't work so well with only two wires, their tech support will confirm that. May be the same for Ecobee?

Do you have 3 wires at the thermostat location?

Steve Minnich

I think he was just referring to the purpose of temporarily bypassing it?

purduealum91

Yes, just during the temporary bypass. Under normal operating conditions, all three are required.

Steve Minnich

Boilermaker, How did it work out?

John Mills_5

Do you have common hooked up? Or just RH and W? From what I could see of Ecobee's wiring, a common is needed. You can ask them 1.877.932.6233

purduealum91

John,

Yes, common is hooked up to the bee3.

I haven't had a chance to put in a continuous call for heat yet. I did notice that when the outdoor temp is in the single digits or less, the indoor temp on the main floor drops by 5 degrees. Any thoughts?

hot_rod

pray for warmer weather

Zman

Do the circulators run continuously during a call for heat or do the turn off with the boiler cycles?

purduealum91

Zman,

I will test the continuous heat this weekend. The outdoor temp during the day has reached the low 30s. I raised the main floor heat to 80 degrees. The indoor temp never got above 75 degrees. Thoughts?

purduealum91

Ran the continuous heat test yesterday. Not sure how to interpret the results.

Here's what I did:
1) turned off upstairs bee3.
2) crossed Rh and W1 wires on main floor bee3 to simulate a continuous call for heat.
3) honeywell zone controllers for both floors left in auto.
4) I have a single taco circulator pump.

Results:
Boiler would not run continuously (would cycle on and off). The temp on the main floor never got above 65.

Any help is appreciated. Did I do something wrong?

Thanks!

unclejohn

I will assume the valve opened since the boiler started. So that leaves air in the system or bad pump. Boiler should cycle off when it reaches it's high limit. The pump should continue too run until the t'stat shuts every thing down.