I'll be ordering a grundfoss15-58 tomorrow. I checked the submittal sheets on both pumps and they are almost identical in mounting size. So that will be helpful, I should just be able to unbolt the pump I have now and install the new one with no modification.
, so I go in the garage and crank the thermostat up to 90. Real quick I opened the firebox door to stir the remaining pieces around so they will burn then I shut everything up. 
![[Hearth.com] I'm building a homemade boiler [Hearth.com] I'm building a homemade boiler](https://www.hearth.com/talk/data/attachments/169/169966-e13c28b6d52611a369d994d2d343f51d.jpg?hash=CLMUprHkpf)
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![[Hearth.com] I'm building a homemade boiler [Hearth.com] I'm building a homemade boiler](https://www.hearth.com/talk/data/attachments/170/170044-93cd721e929d66e5438e131da767d6af.jpg?hash=V_ky63QVpT)
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