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[new builder]

i usally see about ten degree differance at my heat exchanger between supply and return with out purance blower running and usally 20 to 25 differance with furance running just curious what the norm is ? this is a homemade boiler i built and it works perfect just wondering how it compares with everyone eles return temps.

[hondaracer2oo4]

I lose 8 through the loop without the blower going but still feeding the sidearm. I get a delta t across the water to air hx of 25.

[Scott7m]

Delta t of 20 is what we hope for

It can be bigger as long as your running your stove hot enough

[skorpyd]

I'm getting about 5 degrees difference without the furnace blower running, and 20-25 with the blower going also.

[new builder]

Sounds like Im right in the ball park !

[46mech]

Where are you guys measuring these temps? Is it at the boiler or at the exchanger? Also, I've tried an infared gun but the reading jumps around alot because of reflectivity, so I think I may try a contact temp. pen that I use for bearings. What do you guys use for taking your temps.?

[hondaracer2oo4]

I need to revise my temps a little. I use a redi-check smoker wireless temp sensor with two sensors. I believe my return sensor is screwed up. It shows temps of 9 degrees lower then the incoming water temp to the hx. I switched probes and I actually have a 2 degree drop after it goes through my 24x24 water to air hx. My temp drop across the heat exchanger with this discrepency is 15 degree drop on speed 3 for the pump, 18 degree with speed 2 and 21 degree with speed 1. I have ran speed 3 for the past few years. I just started today running on speed 1 because I want to see if there is any noticeable differences anywhere. If there is not I will leave it at speed 1 since it costs half as much in electricity on this speed.

[new builder]

Im running my pump on high also I've thought about turning it down and wondered how it would work. Keep is posted on the results please.

[46mech]

Same here - running on high speed and wondered about running slower. Here's my question. What are the advantages? The only thing I could see was saving a little current on the pump. I just like the lower delta T I get on high speed. Are there some other benefits that I am missing?

[willieG]

depending on the size of your piping, being able to run on a lower speed could prolong the life of your piping...less gpm = less friction= less wear