Hydroair with new EK1 - Struggling with long runtimes

What's bringing on the fan? EK recommends a zone valve with an end switch to energize the fan relay.

Have you checked the Smart Boost function? Settings can be made at the Manager to increase return water temperature to 190° from the normal 170° when a zone has been calling for 25 minutes or more.

Same as EBERATT-ed but I would add one more thing. Ensure that the hot water coils are completely purge of air.

So if you went from 1 circ/zone to a shared circ you may not have enough flow. Check the boiler supply temp and the supply and return temp to the air handler coils and report back

@newhydroek1 , thank you for your post. Excellent comments all around.

Since you commented that the air handler is being controlled by an aquastat "on a pipe coming out of the coil", that is where I would look first. The blower comes on when the water is hot, then it cools off while the blower is running, so it turns the blower off - if that is what you mean by "the boiler is cycling the entire time", then I think you have it largely diagnosed. We recommend using an end switch or relay on the same output as the manager to turn the blower on and off instead. Alternately, the aquastat should be on the inlet to the air handler (set for 130°F/110°F, or if in the attic, set for 160°F so it does not run in hot summer weather). If this is your issue, as an emergency fix, turn the existing return side aquastat temperature down so the blower does not cycle on and off when the zone is on.

Turning SmartBoost on the manager (excellent answer, @HVACNUT) should allow your air handler to run at near maximum output. The higher supply water temperature will allow the blower to extract more heat out of the warm air coil, all else being equal. If your comment "the boiler is cycling the entire time" means that the burner is turning off, then the warm air coil is not extracting enough heat from the boiler; this might mean there is a flow issue (some blockage or air bound as @pedmec noted).

Best,

Roger

@newhydroek1 , is the blower cycling? Your aquastat is not in the correct location and can cause this and poor recovery. Low mass does not affect the output of the boiler, if the supply water is 180°, the coil doesn't know where it came from. Is the boiler bypass valve closed about half way? This will increase the flow out to the zone and reduce the bypass flow back to the boiler. The bypass valve cannot be closed all the way or the boiler will not heat up properly on start up.

The burner turning on and off means that the return temperature is high after mixing with the bypass. This can be low flow to the air handler or low heat output out of the air handler. I trust your air handler air filters are reasonably new/clean as well.

Your zone needs to be purged with high flow or the purging will not be very effective.

Roger

You’re welcome, @newekhydro1. If you notice that the boiler runs longer without the burner shutting off with the bypass valve closed halfway or a little bit more, then you're likely improving your operating conditions.

The base should be level which will allow the boiler to have proper pitch for boiler air removal.

I don't think that you have an issue with draft, because if you had too little draft, the boiler would shut off, and the boiler has very stable combustion, so the chimney will never have too much draft to cause a problem.

Let us know how you make out.

Roger

That's why a 4 wire zone valve is recommended. The zone valve will open and close frequently under a heavy load, so the end switch on a 4 wire zone valve would close to energize the fan relay in the air handler. The fan will start and stop in conjunction with the opening and closing of the zone valve.

Sorry I answered out of turn.

Thank you for your perfect answer, @HVACNUT.
@newekhydo1, thermal purge is based on time and temperature (when the return is cold after the blower takes the heat out). Using the four-wire zone valve or output rely is the correct solution and has been implemented tens of thousands of times. The circulator also runs in pre-heat and for hot water and other zone(s), so you don’t want it running the blower outside of when that specific zone valve is open.
Roger

At design temperature , shouldn't the system run constantly? Shouldn't the system just replace the heat loss. Any setback can not be recovered because at design temperature the system is not capable of delivering this additional heat.