Hot Water Boiler Short Cycling after Aquastat Replacement

ACG_2009

Hi,

I'm running a SlantFin Galaxy gg-150 HEDP with automatic damper, it was installed around 2003.
I have 3 zones (Taco head/valves) (1 upstairs baseboard, 1 downstairs radiant, 1 water heater).
My aquastat is a Honeywell L8148E, I had the older version without the built-in Molex plug and replaced it with what appears to be a newer version with a Molex plug, jumped out.

My Aquastat is high limit only, with the limit set at about 180 - 185.

Note, before this the only issues I was experiencing with the system were a lack of heat at times, and eventually no heat at all due to the relay going bad on the previous aquastat.

After I replaced the controls, my heat and hot water started working great, and still do, however, iI noticed that the boiler might be short cycling. I noticed this because recently, the boiler will fire for only a few seconds and then shut off. I checked the zone heads to see if the boiler was getting calls for heat during these short spurts, and I'm seeing zero volts for all 3 zones. Can someone help me figure out if this is normal or what might be causing it?

Additionally, when I force a call for heat, my boiler gauge only shows the temp going up to about 150-160 degrees and maintains a 15-degree differential before kicking back on again. I'm thinking that the aquastat I installed might have a faulty temp bulb as I checked to make sure that the capillary tubes weren't crimped or bent before inserting into the well.

Thanks in advance for any help you can provide

STEVEusaPA

The bulb may not be making proper contact with the well. But usually when that happens your temperature tends to overshoot.
0 volts means power is going thru them (they are calling). However, what are the end switch wires doing? Are they properly/fully closing? I would ohm them out, and check all low voltage wiring, and especially all wiring that was 'touched' when the aquastat was replaced.
Could also be a bad aquastat out of the box.
Is the temperature measured with a gauge, or by the aquastat? Could be a bad gauge. Newer, better aquastats will have a temperature display.
I don't know what 'force a call for heat' means, but if you jumped out something on the aquastat, I hope you manually open your zone valves.

EBEBRATT-Ed

They also have heat conductive grease or paste you can put on the aquastat bulb which may help

newagedawn

theres a short in the t stat wire or the tstat itself needs to be changed