![[Hearth.com] tell me about boiler temps and pump flows- i talk better than i type btw..](https://www.hearth.com/talk/data/attachments/142/142405-320368706da4784be394244746fd0c50.jpg?hash=zuc0_sKu_p "[Hearth.com] tell me about boiler temps and pump flows- i talk better than i type btw..")
I just fired my boiler for the 1st time ever on Friday moirn the "paperwork" said to set the boiler to 180 @ 18 psi and a 10 deg differential ...... why ?? I set it to 170 and then the 10 ...and the psi hangs at 20,( both the gauge that came with the boiler and my aximon boiler tender), thing is when the boiler shuts down after a call for heat the temp climbs to 175 and stays there... I've had to only add wood 1 time since Friday! 21 to 12 deg outside temps, heating a 4 zone slab in 1200 sqf shop (70degs in here is a bit much !) last call for heat in the shop was Saturday morning at 9am the again last nite at 2am I have two pumps both GF one regular 3 speed after my 4 way valve to run the zones and one the alpha that pumps from the boiler thru the 4way and back .... I put the alpha pump in auto-adap and it burms 43 watts and pumps 11 gpm ...with no call for heat ........... seems mighty high for a pump just pushing a loop with no calls for heat .... how to go about setting the "speeds" and what should I be looking for in return temps (of the water coming back into return ) I have my 4 way set to supply temps between 85 and 110 on a outdoor reset, my return boiler water at 140tell me about boiler temps and pump flows- i talk better than i type btw..
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I just fired my boiler for the 1st time ever on Friday moirn the "paperwork" said to set the boiler to 180 @ 18 psi and a 10 deg differential ...... why ?? I set it to 170 and then the 10 ...and the psi hangs at 20,( both the gauge that came with the boiler and my aximon boiler tender), thing is when the boiler shuts down after a call for heat the temp climbs to 175 and stays there... I've had to only add wood 1 time since Friday! 21 to 12 deg outside temps, heating a 4 zone slab in 1200 sqf shop (70degs in here is a bit much !) last call for heat in the shop was Saturday morning at 9am the again last nite at 2am I have two pumps both GF one regular 3 speed after my 4 way valve to run the zones and one the alpha that pumps from the boiler thru the 4way and back .... I put the alpha pump in auto-adap and it burms 43 watts and pumps 11 gpm ...with no call for heat ........... seems mighty high for a pump just pushing a loop with no calls for heat .... how to go about setting the "speeds" and what should I be looking for in return temps (of the water coming back into return ) I have my 4 way set to supply temps between 85 and 110 on a outdoor reset, my return boiler water at 140
In my radiant floor retrofit I was aiming for about a 20 degree temp differential, depending on what the Alpha pump would do. Turns out on speed 2 it pumps about 2.5 gpm, with 4x 350' loops of half inch pex + manifold, with about 18 degrees differential, using 22w. There is a minor variation in floor temp from the differential, but it is really only noticeable in two locations - under the desk and right in front of the kitchen sink are a degree or two warmer than the rest of the floor.
Average heat output is based on average water temperature, so try all three speeds and see which one gets you between that 10-20 delta range. Should be evident looking at the pump curves and head for your loops.
If you want one setting for the season with your alpha, set it to flow your required heating load with a 20 delta T ... 160 min supply - 140 min return = 20 degree differential. 30 delta T maximum if you bump up to 180 and 10
Average heat output is based on average water temperature, so try all three speeds and see which one gets you between that 10-20 delta range. Should be evident looking at the pump curves and head for your loops.
If you want one setting for the season with your alpha, set it to flow your required heating load with a 20 delta T ... 160 min supply - 140 min return = 20 degree differential. 30 delta T maximum if you bump up to 180 and 10
had it on one ..that was no good ,I put it in auto -a-dap last nite at 7pm ...going to see what that does for it , My 4 way in the shop is set for 85-110 degs on the outdoor reset...I was getting a slug of 120-130 temps at the manifold ,so I moved the sensor things settled down after that and I found that the gf 15/58 3 speed after the valve ,needed to be in the speed 2 spot then the 4way was/could work, well see tonite........I moved my boiler temp to 179 and a diff of 10 ....I seen that moving the diff to much/to low was lowering the psi just enough to have the aximon kick on and bring her up 
>then it would be "to much psi" when she got up to temp
>then it would be "to much psi" when she got up to temp- Status
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