Ecobee SmartSi Repeatedly Shutting Off

jch1

Hi all,

Just had a Peerless Series 63-04 installed with an Ecobee SmartSi thermostat an hour ago. I noticed that the Ecobee seemed to be shutting off every 5-10 minutes or so and began to investigate. It looks like 1) every time the low water cut off performs a routine water level check and 2) every time the water feeder actually provides the boiler with water, power is drawn from the thermostat to these devices, thus shutting off the thermostat. This doesn't seem normal.

Also, because of this, the thermostat "resets" to read 80 degrees and has a standard temperature value. I fear that when this happens, the current heat program will shut off once the thermostat restarts as opposed to "remembering" its previous setting.

Any help is appreciated

jch1

A bit more info- It looks like the low water cut off is running a "check" periodically regardless of whether the boiler is operating. In other words, I just had the boiler running and the thermostat suddenly shut off, so I ran to the basement to check it out. Lo and behold, the low water cut off had the "water level check" light illuminated. Can I disable this somehow? It's interfering with the operation of the system.

Also, I have three wires coming from my boiler and going to the thermostat, if this helps.

BobC

If that is a Cycleguard LWCO there isn't anything you can do except replacing it with a Safguard that does not have the intermittent "feature" we all love so dearly. i just picked up a Safguard on ebay to replace mine with.

Be aware that if something goes wrong, replacing that control could blow your boiler warranty.

Bob

jch1

Yeah, it's a CycleGard CG50 or CGT450 Series. So my only option is to replace the LWCO? This seems unreasonable, doesn't it?

BobC

Live with it or replace it, there is no way to modify the way it works that I know of. I agree it's not a well thought out design.

Bob

jch1

It seems terribly inefficient to shut the system off every ten minutes. On top of that, like I said, it is causing my thermostat to "restart" as well, so its temperature setting may or may not be recalled upon it turning back on. How difficult would it be to install a Safe Guard myself? I suppose I could probably see if the installer would throw a different model on there for me.

BobC

If yours is the 10 minute model it might add 4 or 5 minutes to a heating cycle and that adds up over time. Mine was the 20 minute model so it isn't as bad, the thing is supposed to rezero itself after the boiler shuts down because of pressure or the thermostat but I have not found it to be the case.

Changing it requires unwiring the old and wiring up the new, make a mistake and you could get to buy another one, the safguard costs about $150 new. There is a water sensor that has to be removed and replaced as well.

Bob

jch1

Thanks Bob. The safgard is definitely something that I can install. I still am going to ask if they will put it in for me.
As an aside, from what I've read, the water level sensor is the same for both of these models. Also, I think I will still have the problem of the thermostat shutting off when the low water cutoff actually does come on, so it seems like I will need a thermostat with battery and wired power.

BobC

The water level on the boiler should not come on unless the water has oils in it or the piping is not correct. My boilers LWCO has never come on in 2 years and the previous boiler went 16 years without the LWCO ever cutting the boiler off. Your right that the sensors should be the same, I haven't gotten mine yet so I can't vouch for that.

Has the boiler been skimmed?

Bob

TheRooster

I also have a cyclegard on my boiler and I also had problems with my Nest thermostat turning off during the intermittent check.

The solution, was to run a 24v "common" wire to the thermostat from the transformer.
I have a Honeywell transformer on my Beckett oil burner and the transformer doesn't have a 24v out so I had to take it apart and trace the circuit board. Low and behold, the bottom terminal for the Temp Sensor was my "common". That has since fixed the problem. I don't know how your setup is but you probably also need 24v to power the thermostat during the water level check cycles.

jch1

Thanks guys. The boiler hasn't been skimmed, they are coming back in a few weeks to do that. I am pretty sure they are going to tell me that it's operating normally, since, technically, it is. To rooster, I do have a three wire setup, which includes a C wire to provide power from the boiler. The problem is that when the lwco activates, it draws all of the power from the thermostat, thus shutting it off and causing it to reset. My only options are to get a lwco without this intermittent check that happens every ten minutes, or get a thermostat that also uses batteries in addition to the C wire. That way, when power kicks off, the thermostat will still be on and reading the temperature. However, that won't have an effect on the boiler shutting off every ten minutes.

TheRooster

You have a 24v LWCO? Another option would be to just get a 120v one but for the price, the Safegard might be cheaper.

jch1

According to the installation instructions, i have a low water cut-off for 120VAC Operating Voltage steam boiler.

TheRooster

Ok, so then the LWCO must be killing power to your transformer and not drawing power from it.

Probably the most economical route would be to buy a 24v plug-in transformer (radio shack?) and connect that to your common wire so that your thermostat always has power even if the LWCO kills power to the burner.

You already know your other options, install a Safgard, a thermostat with battery backup or a "dumb" thermostat.

jch1

Thanks Rooster. Again, if I do buy a transformer, I'll still be dealing with the LWCO basically short-cycling my boiler by shutting it off every ten minutes. I think I'm going to have to go with a new LWCO.

TheRooster

Are you sure it checks every 10 min? My Cyclegard checks every 20 and as long as no extra water is needed, the boiler fires up again within 60 seconds.
I checked my 3psi gauge and the pressure is still useable after the boiler is off for 20-30 sec and it takes about that long to build up pressure again after it kicks back on. I think the effect is negligible but maybe some of the pros on the site have another opinion. Basically, your water won't cool off at all if the boiler isn't firing for 60 seconds.
Another thing, and I think it was mentioned above, if you switch out your LWCO, it might affect the warranty on your boiler.

jch1

Since I have a model -1560, it checks every 15 minutes for 60 seconds. The issue with this is that it shuts down my thermostat, and restarts after 60 seconds. My ecobee smart si thermostat then powers up for about 60 seconds, and initially reads a temperature of 80 degrees before it settles down to the actual temp. This takes at least 3-5 minutes. So on the long end, we're looking at about 6 minutes before the thermostat again tells the boiler to kick on. Add the drop in pressure that occurs over this time, and we aren't really generating any steam at the radiators for long before it kicks off again.

Also, I haven't timed it, but I do believe that it's actually checking every ten minutes.

Another aside, it looks like I can activate a "SmartCycle" which will allow the timer to be timer to be restarted when the burner fires. Maybe I'll look into this.

TheRooster

Oh I should check into this "SmartCycle" also. The Cyclegard checks every 20 min regardless wether or not the burner is firing. It sounds like the SmartCycle will at least prohibit the burner shutting down too early in the cycle.

I think I understand your problem fully now but I would still go with a dedicated transformer for your situation. This one from amazon is less than $30
http://www.amazon.com/Honeywell-AT72D1683-120V-24V-Transformer/dp/B000692A58#productDetails

If your thermostat always has power, then there should be no delay to turn your boiler back on after the intermittent water level check.

SMichalczyk

I came to say I'm experiencing very similar behavior to jch1. I have a Burnham MegaSteam fired by a Carlin EZ Gas Pro. The Carlin is only a couple of weeks old because the previous burner (Wayne Combustion) that was installed by the previous home owner was apparently undersized and I went all last winter with barely any heat. When the technician was here a of couple weeks ago installing the Carlin he had jumped the thermostat wire, bypassing my Nest thermostat while fine tuning the combustion. The heat production was awesome and all radiators were very hot. When he left he reconnected the Nest and then things were kind of lackluster. Heat production was definitely better than it was with the Wayne burner, but not anywhere near as good when he had jumped the thermostat wire while fine tuning the install.

I began to take a look at my usage on the Nest and I could see that the heating history was showing tons of short bursts. I decided to investigate further and I noticed that my CycleGuard CG450 was showing the intermittent level test light every 10 minutes. This light would stay lit for 90 seconds. While this was happening my Nest would show the target temp of 72 and an actual temp of 68, but the screen would be black (as opposed to orange) and it would not say "Heating" as it should in that situation. After about 3 minutes elapsing from the intermittent test completing, the Nest would turn orange and show "Heating" again. The Nest would go black again after about 7 minutes when the next intermittent test began. And the cycle repeats.

I have learned that the Nest has a "Minimum On-Off time" that is supposed to "protect" your equipment by trying to prevent short cycling. With a gas heat system, the Nest apparently sets this value at 3 minutes. There does not appear to be a way to change this.

So, basically now I'm stuck in this cycle where the burner fires for about 7 minutes, then is off for about 4.5 due to the intermittent check and Nest Minimum On-Off time.

As you can imagine, it's difficult to build up adequate steam pressure in these conditions.

To confirm my theory that the combination of the CycleGuard CG450 intermittent water level test and the Nest Minimum On-Off Time are preventing me from getting the expected steam pressure and subsequently hot radiators, I removed the Nest from the equation and jumped the thermostat wire...

Boom, just as I anticipated, the burner fires until the first intermittent water level test, the burner stops for 90 seconds, then immediately fires again and will continue firing for 10 minutes until the next intermittent water level test. All radiators are hot all the way across and the house is heating nicely.

I will say, that even without the Nest, it seems idiotic that the burner stops firing every 10 minutes for 90 seconds due to the CycleGuard CG450. I think my next step will be to research how I can wire the CG450 to enable the SmartCycle feature. If I'm reading this correctly, this will start the 10 minute intermittent test cycle timer when the burner first fires when heat is called for instead of indiscriminately testing every 10 minutes. At least this way I will get full 10 minute burner firing cycles between the intermittent tests.

That seems to be the easiest first step. I'll see how that goes and decide if further action is necessary. I'm thinking step 2 would be to figure out how to supply power to the Nest so that even when the intermittent water level test occurs, the Nest thinks the burner is still firing, thus avoiding it's 3 minute Minimum On-Off timer which prevents a call for heat for 3 minutes after the intermittent water level test occurs.

jch1

I actually looked into rewiring the CG to see if the intermittent check could be overridden, but ultimately I decided it would be safer to just purchase a SafGard and install that. I've had no issues whatsoever with it, and don't have to worry about my system needlessly shutting off to perform the water level check. It really is useless, in my opinion.

SMichalczyk

Thanks for the reply. What was the effort level on installing the SafeGuard? I'm not mechanically inclined...

jch1

It was really simple. Identical connections in both devices, so you really just unplug the wires and replug them in the same location to the new device. I chose to use the existing low water sensor that was on the safgard (I believe it's the exact same one, but not sure), but you could remove and replace that.

I'd say it took me 15-20 minutes total start to finish.

BobC

The [robes are the same, if you see any connections that are not on the safeguard call a pro to swap it out.

Bob

SMichalczyk

Is there a particular model SafGard I should be looking for to replace the CycleGuard CG450 I have?

SMichalczyk

Came back to say that I temporarily bypassed they CycleGuard and I'm getting great heat. I have now replaced the CycleGuard CG450 with a SafGard 450 and all is great. The install took 5 minutes.

jch1

Great to hear, and yes, it's a quick and painless installation.