I have an empyer elite 200 outdoor wood boiler. Knock on wood I have had no issues! I have a low loss header set up on the back of the unit with a danfoss valve for boiler return protection. I have noticed that my boiler can be 180 but the water coming out of the supply side header may only be 170 even though my return temp is well above 140. Is it possible that my boiler bypass/primary pump could be pumping less gpm than my supply pump to the storage tank thus causing its own mixing? I have pulled the thermo valve to make sure it is opening and closing and everything seems fine. I also took temp readings with a thermo temp gun to verify temperature gauges were all accurate or at least very close. If I was only heating the house it wouldn't be an issue but heating storage the extra temp could be beneficial.
low loss header/boiler protection
- Thread starter pinto999
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maple1
Minister of Fire
Maybe? My loading unit does both jobs so can't really relate, but think I could almost picture it. But also am thinking the second circ should move water thru the boiler vs. backwards thru the bypass. More info might help like layout & pics. What do you have for circs? That sounds like dt of 40 thru the boiler? That's maybe a bit high which might mean more flow might help. Exactly how much is 'well above 140' though?
I am going to take some pics tomorrow and post them. I run a wilo star 16fx to supply the header. To the storage tank I run 2 grundfos 26-99"s in series. 1 1\4 pex Has to be close to 20 gpm. Not sure what the wilo star would pump at?
maple1
Minister of Fire
Man that seems like huge flow. Don't know anything about your system though. Did you try powering down one of the series circs & see what that does?
Do you have a throttling valve on the boiler bypass leg? It might need throttled more. 'Return well above 140' sounds like there is too much flow going around the bypass loop - should be able to get that close to 140 with the throttling valve.
How long have you had this setup? Was it always like this?
Do you have a throttling valve on the boiler bypass leg? It might need throttled more. 'Return well above 140' sounds like there is too much flow going around the bypass loop - should be able to get that close to 140 with the throttling valve.
How long have you had this setup? Was it always like this?
Just got home started up fire for the evening. Owb is at 169. Water leaving the header is 160. Water returning to the header is 142 . Water entering the house 130 ft. away from Owb is also 160 and return is 142. I shut down 2nd circ. supply water temp stays at 160 however my return water temp drops below 140. Here is a pic of the header/boiler protection unit.
![[Hearth.com] low loss header/boiler protection](https://www.hearth.com/talk/data/attachments/241/241507-b51ed49abbf72a9923eb1fccb328052f.jpg?hash=prJCt6kkIR "[Hearth.com] low loss header/boiler protection")
maple1
Minister of Fire
Where is your owb temp measured at? How are you measuring all the temps? Can you measure temp where water comes out of boiler?
EDIT: I see you don't have a throttling valve on your bypass loop. I don't have a Danfoss, but a throttling valve is most always recommended around here for a Danfoss. You could be getting too much flow bypassing and not enough to your header. Which might let your house loop return water mix into the house supply at the header.
EDIT: I see you don't have a throttling valve on your bypass loop. I don't have a Danfoss, but a throttling valve is most always recommended around here for a Danfoss. You could be getting too much flow bypassing and not enough to your header. Which might let your house loop return water mix into the house supply at the header.
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Water coming out of boiler at green pump is 8 to 10 degrees hotter than water temp at red pump. Verified by thermometer guages as well as temp gun. Are you saying i should install a valve on the heater hose bypass tube? Should the danfoss no close completely after desired return temp?
maple1
Minister of Fire
Search danfoss on here for more info. I could never get my head around it but that's what is being done.
But what is the reason for the header? Seems it is just giving your house return a chance to mix in with the house supply. That's a primary secondary setup but if the primary doesnt carry enough flow or tees dont have enough separation that might be bound to happen.
But what is the reason for the header? Seems it is just giving your house return a chance to mix in with the house supply. That's a primary secondary setup but if the primary doesnt carry enough flow or tees dont have enough separation that might be bound to happen.
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