I think I figured it out

[nate379]

Realized today that the way I installed my outdoor reset this spring, it wasn't working right.

The boiler has 2 pumps for the floor heat. One on the primary loop and another on the secondary. I thought both pumps were controlled off the reset. I don't hardly use the boiler but the couple times I have kicked it on seemed like it was taking forever to warm up the house.

What was happening is pump A would run with the outdoor reset and pump B was only running when the boiler fired. It was being controlled off the end switch.

T Stat calls for heat, boiler runs till it's up to temp the reset is calling for. Pump A and B are running. Boiler shuts down and only pump A runs. Pump A keeps on running and running just recycling colder and colder water. Primary loop would be 150* for example and secondary loop 70*. Without pump B running it won't run hot water through the mixer and the only way that primary loop water cools is from heat lose and maybe a bit of thermal transfer. The reset sensor is on the primary loop so it would think everything is fine while the whole time it was just running 60-70 water through the slab.

Rewired it to now BOTH pumps are run off the outdoor reset. Seems to be working correctly now.

 

[ISeeDeadBTUs]

What boiler is it?

 

[infinitymike]

What is an outdoor reset?

Do I need one?


I'm still in the process of installing my primary/secondary.
I got the Oil Burner side all finished up and running next is the Wood Gun.

I don't see any problems yet but then again don't know what I'm looking for.

 

[Gasifier]

Realized today that the way I installed my outdoor reset this spring, it wasn't working right.

The boiler has 2 pumps for the floor heat. One on the primary loop and another on the secondary. I thought both pumps were controlled off the reset. I don't hardly use the boiler but the couple times I have kicked it on seemed like it was taking forever to warm up the house.

What was happening is pump A would run with the outdoor reset and pump B was only running when the boiler fired. It was being controlled off the end switch.

T Stat calls for heat, boiler runs till it's up to temp the reset is calling for. Pump A and B are running. Boiler shuts down and only pump A runs. Pump A keeps on running and running just recycling colder and colder water. Primary loop would be 150* for example and secondary loop 70*. Without pump B running it won't run hot water through the mixer and the only way that primary loop water cools is from heat lose and maybe a bit of thermal transfer. The reset sensor is on the primary loop so it would think everything is fine while the whole time it was just running 60-70 water through the slab.

Rewired it to now BOTH pumps are run off the outdoor reset. Seems to be working correctly now.

Nice work NATE. Glad to hear you got it doing what you want it to now. What's the weather like were you are right now?

 

[Clarkbug]

What is an outdoor reset?

Do I need one?


I'm still in the process of installing my primary/secondary.
I got the Oil Burner side all finished up and running next is the Wood Gun.

I don't see any problems yet but then again don't know what I'm looking for.

Outdoor reset adjusts the setpoint temperature of your hot water loop. For instance, my oil boiler right now runs until it hits 200 degrees, then it stops until it hits 180 degrees, and then it fires again. When its mild outside, there probably isnt a need for such hot water, since lower temps would satisfy the heating load without overshooting.

The outdoor reset adjusts the water temperature setpoint based on how cold it is outside to try and match the water temperature to your heat load. That way you are always providing just the right amount of heat to your house to offset the losses, rather than always blasting out the hottest water the system can handle. Guys here who have storage would put a 4-way mixing valve on the outlet of the tanks and use the outdoor reset to control the temp that goes out to the system.

There are a lot of other subtleties that are involved, and its usefulness will depend on how the rest of your system is configured. But if you are trying to squeeze the maximum efficiency out of your overall system, they can work fairly well.

In my case, my house is so leaky that my money is better spent on insulation and air sealing, instead of boiler controls. Maybe a few years down the road Ill consider it, but for now I just wish my system was piped up!

 

[infinitymike]

What is an outdoor reset?

Do I need one?


I'm still in the process of installing my primary/secondary.
I got the Oil Burner side all finished up and running next is the Wood Gun.

I don't see any problems yet but then again don't know what I'm looking for.

Outdoor reset adjusts the setpoint temperature of your hot water loop. For instance, my oil boiler right now runs until it hits 200 degrees, then it stops until it hits 180 degrees, and then it fires again. When its mild outside, there probably isnt a need for such hot water, since lower temps would satisfy the heating load without overshooting.

The outdoor reset adjusts the water temperature setpoint based on how cold it is outside to try and match the water temperature to your heat load. That way you are always providing just the right amount of heat to your house to offset the losses, rather than always blasting out the hottest water the system can handle. Guys here who have storage would put a 4-way mixing valve on the outlet of the tanks and use the outdoor reset to control the temp that goes out to the system.

There are a lot of other subtleties that are involved, and its usefulness will depend on how the rest of your system is configured. But if you are trying to squeeze the maximum efficiency out of your overall system, they can work fairly well.

In my case, my house is so leaky that my money is better spent on insulation and air sealing, instead of boiler controls. Maybe a few years down the road Ill consider it, but for now I just wish my system was piped up!

So is it a aquastat that senses outdoor temp.
or is it a mixing valve that senses outdoor temp.
or is it a thermometer that wires in to one or both of the above.

My system is in an attached garage/ shop that is only insulated and sheetrocked on 1 side, the back and above the unit.
Basically the rest of the 500 square foot area is wide open with no insulation and 2 very leaky overhead garage doors.
eventually I hope to change the 2 overhead doors and insulate the remaining walls and ceiling.
But I feel the money would be better spent on adding insulation to the attic above my living space.
I am considering building 2 walls to enclose the unit in a "boiler room".

 

[Clarkbug]

Its a temperature sensor thats mounted outside that then adjusts a mixing valve or a controller to control system temperature.

Insulate your living space first so you feel more comfortable. No sense having the boiler feel more comfy than you and your family do. So keep the house warm, then when you can, make an insulated boiler room.

 

[nate379]

Outdoor reset can be a couple different setups.

Mine measures outside temp and fires the boiler to xxx temp. For example if it's 30* outside it might only heat the water to 140* while if it's -10* it would heat it to 190*

My garage is insulated the same as the house, r21 walls, r60 attic. I did just finish building a closet for the boiler, but for the simple fact of keeping stuff off it. I melted the foam pipe insulation in a few spots from welding sparks flying on it.

 

[nate379]

Snowy. If it's been anything like that last 2-3 weeks we are going to be buried this year.

Nice work NATE. Glad to hear you got it doing what you want it to now. What's the weather like were you are right now?

 

[ISeeDeadBTUs]

I sometimes wonder if outdoor control is not the best where we have a wood hydronic and a fossil BU. For example, the wood is always going to heat to say 170-190 °F irrespective of outside temps. And though you CAN heat your floor with tubes running less-hot water, seems it will take longer, intuitivly. Plus, when it gets warmer out - like now - the cooler water running through the tubes actually makes the house seem less warm. Since we are supplying 180 °F water 24/7 anyway, why not use the warmest water we safely can to run through the tubes, thus getting the zone shut off quicker.

The odd thing is, my outdoor control was designed for a system of continuous circulation. It's the European way. But we use stats instead of constant circ.