System 2000 EK1 cold weather problem

regalflyer

Our circulator seems to run all the time and the return line temps don't seem much different than the output. I don't understand the reason for the hot water heat exchanger being in the bypass loop. Registers at the end of the house never seem to get hot enough, and even the registers closer to the boiler don't see very high temps. Standard embassy baseboard about 2" fins, 3/4 " pex loop.

STEVEusaPA

Are you sure the circulator is working properly? System purged of all air?
Did the system ever work correctly?
How long is the entire loop, from boiler thru baseboard, back to boiler.
What info is the Manager providing you.

regalflyer

System seems fine, no air, pressure gauge good and manager lights are happy. We have only used the system in "shoulder season" since the house was built. I had to shut down the wood stove for a repair and we got hit with cold temps. That's when I noticed the problem. The house is 65 feet long with the boiler on one end. Do I need another circulator? We are running 3 zones, about 1800 sq foot.

STEVEusaPA

Hard to diagnose without seeing everything. It's possible that the boiler is undersized, but more likely the piping and/or circulator is undersized, or there is too much radiation to recover.
How are the 3 zones piped? Circulators or zone valves?
What happens if you run just one zone? Is the boiler coming up to temperature, is that zone getting warm?
Are you trying to heat the zones and there's a call for the domestic hot water.
Recovering a larger temperature swing usually takes hours.
Can you post a pic showing the boiler and all the near boiler piping?

rick in Alaska

Does the boiler come up to 180? And, has this worked before? You said one circulator is running but not heating, and you have three zones. Are the other zones on individual circulators, and are they ok?
Rick

regalflyer

We have zone valves for everything running on the main circulator.
I discovered the bypass was open all the way, doesn't that shunt most of the flow away from the zone valves?

STEVEusaPA

regalflyer said:

We have zone valves for everything running on the main circulator.
I discovered the bypass was open all the way, doesn't that shunt most of the flow away from the zone valves?

Yeah that would do it

lchmb

dont shut it completely...

billtwocase

I would leave it fully open. Is it a digital or classic manager? Pics?

regalflyer

The manual says to start at half way closed and adjust so returns don't go below 120 when a zone opens. That's for hot water baseboard copper applications. I can't test it without another cold day with the wood stove shut down. That's why we never saw a problem before, but something is not right if our 40k btu output wood stove can keep the house warm almost down to 0 and the boiler can't get enough heat into the registers by itself.

i will have to wait for another cold snap to do some testing.

It is the digital manager-

JoeHNJ

Most issues do not involve the digital manager. I will post some further thoughts shortly.

JoeHNJ

If the boiler is reaching 180F and the baseboard is not, there is a probably a flow issue. This could be bad zone valves, possibly the motor is not working or the valves are stuck and the valves are bypassing slowly. An easy check is to manually open the zone valve and the piping downstream should get hot very quickly.

I read the “pressure gauge is good,” and if this means the system has 12 psi cold and pressure builds as the water expands, that may be ok for a one or two story home. Double check to make sure the system is not low on water – that could cause these same symptoms. With possible flow issues, if the system hasn't been run for a while, purge each zone individually to make sure there is no air or obstructions.

As a general setting, for baseboard zones, we recommend the bypass ball valve be closed half way. This uses more of the circulator head to drive through the pressure drop of baseboard and still works perfectly for hot water with a plate heat exchanger in the bypass. Primary/secondary piping and large water volume radiation should have the bypass fully open. For reference, the heat exchanger can be in the bypass or on a zone; in this home, it’s in the bypass, which simplifies the piping as there is no zone. We recommend the heat exchanger as a zone for hard water applications.

Regarding boiler sizing, any of our boilers should easily heat an 1800 square foot home. If the burner shuts off during even once during the heating cycle, that means the baseboard cannot take all of the heat out of the boiler, which would generally indicate a flow issue through the baseboard or undersized baseboard. If the burner never shuts off (runs 24/7 without turning off even once) and the home is not increasing in temperature, this means the baseboard can take all heat the boiler can make, indicating the boiler is undersized (this is very rare).

DanHolohan

EK service at its best! Thanks.

regalflyer

Thanks Dan,
The boiler is definitely shutting off with the circulator running and the zone still calling. We are plumbed with WIRSBO pex at 3/4", am I losing too much flow vs 3/4" copper? That's what I am thinking now?

We also run basement radiant in another zone with its own manifold and circulator with a mixing valve and that zone runs perfectly.

JoeHNJ

You say the radiant zone runs perfectly, how many additional zones? The pex should work fine. Can you verify the zone valves are open and the supply and return pipes are getting hot for those zones?
JoeH
Energy Kinetics Technical Support

regalflyer

Everything runs fine as long as the house is not too cold. I have either poor radiation or bad flow- the radiators can't seem to draw down the boiler temp, and the burner shuts off.

I cannot test until we get cold enough again, and I also have to shut down my wood stove so the boiler is the only heat source.

JoeHNJ

Has the system ever operated sufficiently in cold weather?

regalflyer

sorry, I believe the installation has never really been able to put out a lot of BTU. We started using a woodstove to save fuel and the system is used for standby vacation temps (55) when we are gone and domestic hot water. It also heats a zone if the stove is not warm enough. It was very noticeable when we hit single digits and the wood stove was down for maintenance.

This is an installation issue, not something that just happened after years of good operation. Again, it does not really show up well because it will keep the house at 68-70 but cannot drive it higher than that when it is cold. We only started investigating because our wood heat was out during a cold snap, and it showed up then.

Brewbeer

regalflyer said:

... it will keep the house at 68-70 but cannot drive it higher than that when it is cold. ...

If this system has outdoor reset, and it is properly set up, we wouldn't expect it to heat the house past 70 degrees, no matter how high the thermostat is set. Also, the temps of the emitters would seem pretty low on mild days, with the warmest emitter temps appearing during the coldest weather.

Is this house well insulated?

billtwocase

No outdoor reset on these. Honeywell or Erie zone valves on this?

regalflyer

Erie

regalflyer

Let's kill this discussion, simple measurement shows that the house has insufficient radiation. The System 2000 is working fine. Heat loss is calculated at 55,000 BTU/hour and I have about 42000 max radiation.

Thanks folks, now have to find higher output radiation.