Wiring Hoyme Make Up Combustion Air Vent to 5 zone Peerless hot water boiler

Speedsmith

Hi, thanks for letting me join, my question refers to adding a combustion make up air vent to my boiler, equipment is:Peerless 85-140-WPC-H, hot surface ignition.Honeywell Aquastat L8148E

4 Zone ( Honeywell valves ) with AT87A transformer wired per:

I plan on purchasing: HOYME Motorized COMBUSTION AIR CONTROL DAMPER – VERTICAL MOUNT – 24VacI've reviewed their instruction and contacted them requesting hook up with my specific equipment but the said to refer to the instructions available.

My question is I don't think any wiring diagram in Hoyme's instructions apply to my set up as with 5 Zone valves I've got T fed with the AT87A transformer so when the thermostat makes the zone valve motor energizes and and closes the end switch(each side of the 5 switches are wired in parallel) terminating at TV & T of the aquastat so one zones thermostat calling for heat the aquastat's transformer initiates the boiler start. Here's the recommendations from Hoyme, I like the last one using the aquastat as a "proving" switch but ( could it be that simple )  just to use the burner outputs of the aquastat. but in this scenario the aquastat relay would already be pulled in, the circulator pump would be running, exhaust vent damper opening  and the surface ignition heating  ? Sorry, tried to snip and post just the wiring diagrams but couldn't, here's a link to the manual
https://hoyme.com/wp-content/uploads/2023/01/Hoyme-HOM-installation-instructions-switch-type.pdf

Thanks, Jim

EdTheHeaterMan

The zone valves have nothing to do with the make up air operation. That control system needs only to be connected to the L8148 control.

Let me look at the Homye instructions and see what I can come up with.

When reading the Hoyme instruction booklet you will need to substitute the word thermostat with the words zone valve end switch. That is because the L8148 is being controlled by the zone valve end switch where a thermostat for a one zone system would normally get connected

EdTheHeaterMan

What is the last 4 numbers of your L8148E XXXX control. That will determine if it has the 15 VA transformer or the 40 VA transformer. This is important because your zone valve diagram indicates that you have an auxiliary that is connected to 5 zone valves. That is the maximum amount of zone valves that you can have on a 50 VA transformer (4 is the maximum you can have on a 40 VA transformer). VA is a measurement of a small amounts of watts. and the transformer for the zone valves can not have any more load connected because it needs more watts (or VA) to handle all 5 valves. there is no extra watts left to connect the damper.

So I need to know what transformer is on your L8148E control in order to recommend the proper wiring diagram. You may need a second auxiliary transformer for the damper to operate properly if you control has the smaller transformer.

See the difference in the transformer on both these L8148 controls here (Green Arrow)

EdTheHeaterMan

This is what I have come up with based on the following:

1. Peerless boiler with L8148E may not have a large enough transformer to operate the damper
2. A separate 24 VAC transformer is needed for the Hoyme SF1
3. There is one appliance (Peerless boiler) with one L8148E
4. All the "End Switch" or Red wires are wired parallel to operate the boiler (meaning any or all the end switches can operate the boiler) and are connected to T and Tv on the L8148E

Zoom in to see the details

1. Remove the "End Switch" or red wires from T and Tv on the L8148E
2. Connect one of the end switch wires to #5 terminal on the Hoyme terminal board
3. Connect the other end switch wire to #1 terminal on the Hoyme terminal board
4. Connect the Auxiliary transformer C to #5 on the Hoyme terminal board
5. Connect the Auxiliary Transformer R to #3 on the Hoyme terminal board
6. Connect Tv from the L8148E to #2 on the Hoyme terminal board
7. Connect T from the L8148E to the #5 on the Hoyme terminal board

This wiring follows the instructions on page 4 of the Hoyme manual and step #9 in Important to check that the auxiliary transformer for the damper and the transformer from the L8148E are in phase. If you need to reverse the wires because the transformers are out of phase, you should do it at the L8148E by swapping the Tv and the T terminal wires