Hey folks, it's been a short while. I hope all of you are doing well. It's heating season again here and I have more questions for the hive mind.
I have a Frontier 150 OWB, it's manufactured somewhat locally by a machine shop called "Carson City Machine Shop". I mention this because it's nearly impossible to find information on this stove. It has a 150 gallon jacket, and is very similar to a Woodmaster.
My loop is about 320' of 1" pex counting both supply and return. It has a rise of about 15 feet, 12 feet after it leaves the boiler. It goes up through my shop and then back down underground again and into the house. The heat exchangers in the house are 3/4" copper and there is a water to water HX for domestic hot water and there is a 17x22 air to water for forced air heat. The HX's are in series with the domestic water first, then the forced air, then the loop goes back out of the house and I have a unit heater next in the shop and then back down and to the boiler return.
When I got the boiler it had a taco 0007-xxx. The boiler didn't have any pressure gauges, but it seemed like the pump was struggling. The local OWB dealer thought I probably needed to step up to a taco 0011-xxx, so I did.
All year last year I had a lot of water loss. If I tried to run the jacket at 165°F, the was constant stream from the boiler vent and I had to add about 30 gallons a week. Many times I felt like the pump wasn't working correctly, but I had no pressure gauges. There were several times where the boiler was hot and neither the supply or return felt particularly warm, and I'm talking right at the pump. If I cycled the return side valve, the pex would get scalding hot in a heartbeat, but it would cool back off. I don't think the pump was priming.
This year I cleaned out the boiler jacket and installed pressure gauges on the supply and return. The loop has less than 4psi even with the return closed and the pump essentially deadheaded. If I cycle the return, the pump will briefly hit 50psi, then fall back off again. I get flow from a drain on the return, but it's just barely above a trickle.
I worked at a chemical plant for 22 years and have operated hundreds of centrifugal pumps. I'm 99% sure this thing isn't primed, but it doesn't sound like it's cavitating and it does produce some flow. I have tried every trick I know from my days operating a chemical plant, and I can't get it to prime.
The pump does not have a valve immediately at it's discharge. I'm picking one up from the big box store today. I've been trying to get it to prime using the return valve, but that's a lot of line to pressurize. The pump also does not have a strainer in line, and if I can find one, I'm putting one in as well.
The pumps suction side goes into a dip leg in the jacket. I've blown it down with compressed air to ensure it's not restricted. There is a check on the return side, which I think based on pump location below the water line and the checks, that once the jacket is full the pump should essentially be below the water line and should be completely flooded. It makes no sense that it will not prime.
I'm really looking for any advice you folks can give. I know this is long winded, and I apologize, but I'm trying to give the most accurate picture with the greatest amount of pertinent data as possible. I've also considered putting the old 0007 in the return line, but from the pump curves it sure seems like the 0011 should be more than capable of this loop.
Thanks in advance folks. I really appreciate your time.
Jason
I have a Frontier 150 OWB, it's manufactured somewhat locally by a machine shop called "Carson City Machine Shop". I mention this because it's nearly impossible to find information on this stove. It has a 150 gallon jacket, and is very similar to a Woodmaster.
My loop is about 320' of 1" pex counting both supply and return. It has a rise of about 15 feet, 12 feet after it leaves the boiler. It goes up through my shop and then back down underground again and into the house. The heat exchangers in the house are 3/4" copper and there is a water to water HX for domestic hot water and there is a 17x22 air to water for forced air heat. The HX's are in series with the domestic water first, then the forced air, then the loop goes back out of the house and I have a unit heater next in the shop and then back down and to the boiler return.
When I got the boiler it had a taco 0007-xxx. The boiler didn't have any pressure gauges, but it seemed like the pump was struggling. The local OWB dealer thought I probably needed to step up to a taco 0011-xxx, so I did.
All year last year I had a lot of water loss. If I tried to run the jacket at 165°F, the was constant stream from the boiler vent and I had to add about 30 gallons a week. Many times I felt like the pump wasn't working correctly, but I had no pressure gauges. There were several times where the boiler was hot and neither the supply or return felt particularly warm, and I'm talking right at the pump. If I cycled the return side valve, the pex would get scalding hot in a heartbeat, but it would cool back off. I don't think the pump was priming.
This year I cleaned out the boiler jacket and installed pressure gauges on the supply and return. The loop has less than 4psi even with the return closed and the pump essentially deadheaded. If I cycle the return, the pump will briefly hit 50psi, then fall back off again. I get flow from a drain on the return, but it's just barely above a trickle.
I worked at a chemical plant for 22 years and have operated hundreds of centrifugal pumps. I'm 99% sure this thing isn't primed, but it doesn't sound like it's cavitating and it does produce some flow. I have tried every trick I know from my days operating a chemical plant, and I can't get it to prime.
The pump does not have a valve immediately at it's discharge. I'm picking one up from the big box store today. I've been trying to get it to prime using the return valve, but that's a lot of line to pressurize. The pump also does not have a strainer in line, and if I can find one, I'm putting one in as well.
The pumps suction side goes into a dip leg in the jacket. I've blown it down with compressed air to ensure it's not restricted. There is a check on the return side, which I think based on pump location below the water line and the checks, that once the jacket is full the pump should essentially be below the water line and should be completely flooded. It makes no sense that it will not prime.
I'm really looking for any advice you folks can give. I know this is long winded, and I apologize, but I'm trying to give the most accurate picture with the greatest amount of pertinent data as possible. I've also considered putting the old 0007 in the return line, but from the pump curves it sure seems like the 0011 should be more than capable of this loop.
Thanks in advance folks. I really appreciate your time.
Jason