System 2000- baseboard heat after Hot Water - even when heat is off

locust

Issue: after hot water call, the system is sending water to the baseboards. This happens if thermostat is set to HEAT or OFF

We’ve had the system for 12 years, never noticed this especially in the summer when we specifically turn the thermostat off.

thermostat is the same one used when system installed. Ritetemp, programmed, but not smart. New batteries. 

light shows up for Hot water, burner  kicks on (light is on) then Circulator light comes on (and runs) Hot water is then directed to zone 1 (only one zone) but the zone 1 light is not on. 

Background, other relevant information:
- just had heat pumps installed, Mitsubishi hyper heat with kumo cloud integration. 

- kumo cloud was supposed to handle the handoff from heat pump to oil furnace at 20 degrees. 

- ran the system for two weeks, oil furnace was not kicking on (and it should have as temps were in the teens) 
- during this time baseboards never came on (even after hot water usage). 

Heat pump tech, came out, determined there might be issue with kumo cloud; so he disconnected the kumo cloud. He may have done wiring changes?

we also just had the system serviced, cleaned. We described the issue, he said that was normal to disperse after the hot water call, but did not address when system was off. 

Now we have “free” heat after hot water is used. Which is fine in winter if system is set to HEAT; but I’m concerned that this is not good come summer. 

Any thoughts recommendations? The heat pump company is coming back in two weeks with a Mitsubishi service tech;  looking to have a better understanding. 

locust

Here is a picture of lights after hot water has been used. Thermostat reads, 67 in house, target temp is 60. Baseboards are receiving hot water. 

Ironman

You probably have a stuck flow check - or none in the domestic charging loop.

HVACNUT

Its not shown in the pic but there's zone valves attached to the copper manifold. One seems to be stuck open, from a wiring issue or a faulty actuator. 
There is also a purge zone setting in the Energy Manager. It can dump the leftover heat into a space heat zone, but its usually set to dump it back into the water heater. Unless someone played with the dip switches, that might not be the problem. 
Unless it's the same company, don't expect the burner tech to know much about the Mitsu system and how its integrated. 

GW

Well thanks @Youngplumber. Seems like the other pros have chimed in. 

GW

Ahhh Mitsu integrated control. Ok then. A little hard to diagnose over the phone. If the boiler thinks it’s making domestic hot water but the energy is going to the heating zone, somebody miss wired something or there’s been a  mechanical failure. 

locust

Thank you all!

@GW @HVACNUT

Does the dip switch determine where it purges to?  Added picture of whole system. I see there are switches under the silver box on zone 1. 

Seems as though the boiler fires when we use any hot water even briefly washing hands (don’t think that is normal). We are getting and have plenty of hot water.   After call, it circulates to the baseboards, but would say it feels different than when it is running for a real heat call - that is to say the baseboards heat up, but not for an extended period of time. 

For now the kumo station is not connected so issue seems to be related to the boilers current wiring or switch state. 

Is there test I can do to help determine?  I’m considering too calling the company that installed it (service tech is current oil company not our original one that installed the system 2000). 

GW

Im not familiar with S2000 post purging into a heating zone. That doesn’t seem normal.

Like you said- this hasn’t happened in the past. Someone may have mis wired a zone valve. zone valves need power to open. 

He pulled the Kumo—- are we taking Kumo Station for your integrated system? If yes, are all the switches (on top of the control) set to “off”? 

Or, someone changed a loop or did some piping, and you’re getting some gravity flow. Just tossing some guesses out there 

locust

@GW - thank you. 

The kumo station is still there, but the wiring that goes from it into the S2000 energy manager is no longer connected. 

The issue that all started this was the kumo station did not seem to switch over to the boiler when the outside temp was 20 or below. The channel 1 was set to Auto

GW

I would recommend switching it to off, just to eliminate that as a possibility. Again, I am just throwing guesses out there. Sometimes it’s piecing together what happened when, to figure out what’s causing this. Other times it’s a simple mechanical failure.

Roger

Thank you @locust and everyone for your posts. 

The right hand side lights for the zone outputs on the Energy Manager indicate which zone(s) will be receiving heat in post purge or while actively heating.  If the light is not on for that respective zone and it is receiving heat, then there is a bypassing zone valve or it’s mis-wired.
Power stealing thermostats can sometimes give a false call for heat, but you would see a brief thermostat light on the Energy Manager (left side) and that zone output light would have to be on to heat that zone.

That’s all there is to it.

Your initial photo shows the preheat stage for hot water - no zones are on/outputting. If the zone is heating at that time, then the zone valve is bypassing.

If your tank is calling whenever you have a draw for hot water, your heating professional should check the tank thermostat to make sure it is not set to low and that it is not malfunctioning.

To clarify points on several other posts, the manager typically purges to the last zone that called, which could be heat or hot water. If a Display Manager is used and it is set for multi-purge, it can also purge to any zones that finished heating within the past 20 minutes. It will never purge to random zones or ones that have been off for more than 20 minutes.

Best,
Roger 

Zman

One thing for sure, the ghost heat is not free....

locust

@Roger

Thank you for clarification. 

When hot water is called Left lights up as you indicated. Then later the right lights up and the circular light is on. The Zone 1 is not lit up but is receiving heat. 

New issue that we just discovered (had not used heat until this morning)

This morning the heat was called, the light on the left came one, then later the light on the right came on with the circular. The baseboards did revive heat but the silver box on the zone 1 valve was making a clicking noise the whole time. It only stopped after we turned down the heat to below the set temp reducing the call for heat. 

Is this the bypass valve issue?  We only noticed this just after the furnace was cleaned. 

Thanks in advance and thanks for everything, also calling the service company but looking for insight and understanding as well. 

Thanks

Roger

You have your answer, @locust - the zone valve is not functioning properly so it most likely was at least partially open when it should have been closed or off. Diagnostics are always much easier when you catch it in the act!

Ask your service company to bring out an Erie pop-top zone valve. The top with the motor and wiring can be removed and replaced without changing the valve body. The valve is moved to the manual open position and then the button on the side is pressed and the enclosure and motor simply "pop" off for easy replacement. Sometimes service companies want to change the entire valve in case there is a problem with the valve stem paddle or valve body.

As a general comment for this thread, the same symptom can happen with zone circulators if the check valve becomes stuck open, or if the zone valve is left in the manually open position. For reference, cycling the power to Energy Manager (left hand switch on the junction box or the emergency switch in the home) with reset all of the zone valves so they will not be stuck in the manually open position. The zone valves will also come out of the manually open position after a thermostat call heats the respective zone.

Thank you,
Roger