need help in cny

[jeeptj19992001]

think i found problem

http://www.centralboiler.com/Tech/C220.pdf
look at this diagram, notice circ pump on furnace side of heat exchanger, mine does not have that, mine looks like gravity feed, so the boiler water is not getting the heat it should. have a extra circ pump in the basement
looks like i might do that this weekend.

 

[mga]

look at it this way......

your LP boiler heats the water when the system calls for heat. the HIGH limit is set at a certain temperature to turn off the flame so that the system does not over heat, yet, it's high enough to produce efficient heating.

the LOW limit tells the LP boiler flame when to re-heat the water because it's too "cold" and needs to be heated up.

your pump will still run until the thermostat no longer calls for heat.

basically, your OWB is replacing the flame in your LP boiler by keeping the water hot in the exchanger. the system should be operating as it normally does when your thermostats call for heat.

first: (without using the OWB) does your LP flames still go on and off and at what temps? your system should have both a pressure gauge and a temperature gauge.

second: your OWB must heat the water in the exchanger at the same temp as does the LP boiler's flame.

 

[mga]

http://www.centralboiler.com/Tech/C220.pdf
look at this diagram, notice circ pump on furnace side of heat exchanger, mine does not have that, mine looks like gravity feed, so the boiler water is not getting the heat it should. have a extra circ pump in the basement
looks like i might do that this weekend.

you mean the "wrap around pump"?

 

[jeeptj19992001]

look at it this way......

your LP boiler heats the water when the system calls for heat. the HIGH limit is set at a certain temperature to turn off the flame so that the system does not over heat, yet, it's high enough to produce efficient heating.

the LOW limit tells the LP boiler flame when to re-heat the water because it's too "cold" and needs to be heated up.

your pump will still run until the thermostat no longer calls for heat.

basically, your OWB is replacing the flame in your LP boiler by keeping the water hot in the exchanger. the system should be operating as it normally does when your thermostats call for heat.

first: (without using the OWB) does your LP flames still go on and off and at what temps? your system should have both a pressure gauge and a temperature gauge.

second: your OWB must heat the water in the exchanger at the same temp as does the LP boiler's flame.

will look into those items tonight when i can see the system

 

[jeeptj19992001]

you mean the "wrap around pump"?

yep

 

[mga]

yep

so....maybe we're getting someplace here! what you're saying is there is no circulating pump between the LP boiler and your heat exchanger.

or, is it plumbed so that the circulating pump on the LP boiler circulates the heat exchanger water when it's running? (not an efficient way to have it)

 

[sstan]

sorry about jumping in

sorry about jumping in .. but this is of interests to me. I am going to do my install in a couple weeks .. 50 plate water to water exchanger for my existing oil boiler. I saw the central boiler diagram and the wrap around pump confused me. I am hoping I do not need it. My oil burner set up is four zones and each sone has it's own pump. My understanding is that boiler keeps the water at 150- 180 degrees and a pump will come on when that sone needs heat. My plan was to run the OWB pump continuously through heat exchanger but no additional pump on oil side. common sence tells me that if no zone calls for heat no water is circulating on oil side and will not pick up much heat from heat exch and the oil burner could kick on .. but since one of the zones on the oil side is for domestic HW I am thinking one of the four pumps will kick on often enough to circulate the water and there is also the convection factor... does anyone have this type of set up or thoughts? Am I all wet? also I am still confused on which side the HX goes in? My oil burner has a pipe on top going to expansion tank then splitting to the zones. comes back from zones to pumps (suction I am thinking).. dumps into a manifold then to bottom of boiler ... this is the line I plan on putting the HX in ... is that right?

 

[sstan]

hoipefully a this will work .. a photo of my oil burner .. excuse the junk...

 

[itn]

i have a similiar set-up that u talk about. i am still a bit confused about what your talking about though. First off do u have a heat exchanger in the system from your outside boiler or does it bypass your system with a control valve when the outside boiler is running and the inside boiler is not running? sorry bout that i re-read it again and see u have a heat exchanger. is the lp boiler pump shutting off at proper thermostat setpoint or does it continue to operate? this is how i break it down- the lp boiler pumps job is to circulate the water when the thermostat says the house needs heat. the aquastat controls the water temp by firing your lp boiler to maintain whatever that setpoint is. the zones are regulated by you to determine if you want more water to flow through the area they supply. so say if your bedroom is controlled by a single zone and your thermostat is in your living room it is possible to make your bedroom a lot hotter than your living room.

 

[sstan]

well I have nothing in yet .. just starting my install .. trying to figuer out what leg of the oil burner the exchanger goes in.

steve

 

[jeeptj19992001]

i have a similiar set-up that u talk about. i am still a bit confused about what your talking about though. First off do u have a heat exchanger in the system from your outside boiler or does it bypass your system with a control valve when the outside boiler is running and the inside boiler is not running? sorry bout that i re-read it again and see u have a heat exchanger. is the lp boiler pump shutting off at proper thermostat setpoint or does it continue to operate? this is how i break it down- the lp boiler pumps job is to circulate the water when the thermostat says the house needs heat. the aquastat controls the water temp by firing your lp boiler to maintain whatever that setpoint is. the zones are regulated by you to determine if you want more water to flow through the area they supply. so say if your bedroom is controlled by a single zone and your thermostat is in your living room it is possible to make your bedroom a lot hotter than your living room.

in a nut shell, OWB, all the zones work correctly have 6 zones with 6 pumps to serve those zones. but i feel, maybe i am wrong, but my lp boiler should never turn on. i am using a heatmor 100cc heating capacity for 3000 sf , house is 2000 sq. ft heated area. i set the aqua stat to 120 (lowest setting), so the furnace should only turn on when the water gets below 120 degrees.
when running the OWB, there is no way that the water coming into the house from the boiler, should be less then 120 degrees. ( i know the dumb ass owner who installed the system did not insulate the supply pipes) so i have some heat loss there. so i think i am not getting a good transfer of heat through the heat exchanger. there is no pump to push the water through the furnace side of the heat exchanger side, so when all the rooms get the heat they need, all the pumps stop, so no water is going through the furnace, so the furnace water cools down to below 120 degrees, so it kicks on the furnace to bring the water temp up. i will take some pictures of the system this weekend and show ya what i got.

 

[jeeptj19992001]

so....maybe we're getting someplace here! what you're saying is there is no circulating pump between the LP boiler and your heat exchanger.

or, is it plumbed so that the circulating pump on the LP boiler circulates the heat exchanger water when it's running? (not an efficient way to have it)

there a zone pumps, but when the zones are not running, there is no circulation
yep that is what i got


the way the zones are set up
there are two manifolds, one for supply one for return, there is also a bypass for those manifolds, so that when the pumps are not running the water does not "dead end"
so the supply leaves the furnace, goes to the heat exchange. which goes to the suppy manifold to the 6 zones, (and bypass) zones all collect in return maifold and go back into furnace.
so when the zones are not pumping there is no way that the water is pumping through the system, so there is no heat transfer through the heat exchanger, so the water cools down, and the furnace says i am cold and need heat.
i think that is all.

 

[itn]

in a nut shell, OWB, all the zones work correctly have 6 zones with 6 pumps to serve those zones. but i feel, maybe i am wrong, but my lp boiler should never turn on. i am using a heatmor 100cc heating capacity for 3000 sf , house is 2000 sq. ft heated area. i set the aqua stat to 120 (lowest setting), so the furnace should only turn on when the water gets below 120 degrees.
when running the OWB, there is no way that the water coming into the house from the boiler, should be less then 120 degrees. ( i know the dumb ass owner who installed the system did not insulate the supply pipes) so i have some heat loss there. so i think i am not getting a good transfer of heat through the heat exchanger. there is no pump to push the water through the furnace side of the heat exchanger side, so when all the rooms get the heat they need, all the pumps stop, so no water is going through the furnace, so the furnace water cools down to below 120 degrees, so it kicks on the furnace to bring the water temp up. i will take some pictures of the system this weekend and show ya what i got.

it sounds as if possibly your heat exchanger is installed in the wrong spot for what you are trying to do. mine is plumbed direct, but i would think you would want your exchanger as close to the lp boiler water supply as possible so your furnace didn't kick on. my lp boiler does kick on occasionally when it has not ran for longer periods of time. and it will kick on the first time i fire it up for the season until it senses tha 190 degree water from my owb then the aquastat shuts the gas off. maybe you could try shutting your gas off and see how it operates. central boiler's website shows a couple of examples of how a person could hook up their boiler. maybe that could help.

 

[jeeptj19992001]

it sounds as if possibly your heat exchanger is installed in the wrong spot for what you are trying to do. mine is plumbed direct, but i would think you would want your exchanger as close to the lp boiler water supply as possible so your furnace didn't kick on. my lp boiler does kick on occasionally when it has not ran for longer periods of time. and it will kick on the first time i fire it up for the season until it senses tha 190 degree water from my owb then the aquastat shuts the gas off. maybe you could try shutting your gas off and see how it operates. central boiler's website shows a couple of examples of how a person could hook up their boiler. maybe that could help.

did that a few post back,

http://www.centralboiler.com/Tech/C220.pdf
look at this diagram, notice circ pump on furnace side of heat exchanger, mine does not have that, mine looks like gravity feed, so the boiler water is not getting the heat it should. have a extra circ pump in the basement
looks like i might do that this weekend.

 

[sstan]

plumbing in the OWB

I have been reading the thread and post by Jeep ... basically my install was going to be very similar to his. 4 zones each with a pump ... only run when a zone calls for heat. I see the problem that if no zone is calling for heat then the oil boiler never really picks up any heat from the heat exchanger and the boiler could come on to keep the water in there up to the min temp... it does this all summer long ... but since one of my existing zones is for my domestic hot water that pump comes on a lot ... thus water will circulate through the exchanger. Also I assume some natural convection will happen. I am curiose if anyone has installed like this and is the oil burner comming on a mojor problem? It would seem that if it's cold enough for us to be running the OWB then one of the zones will be looking for heat and circulating the water! I really do not want to go through the expense of putting in another pump and making the instll more difficult!

 

[jeeptj19992001]

I have been reading the thread and post by Jeep ... basically my install was going to be very similar to his. 4 zones each with a pump ... only run when a zone calls for heat. I see the problem that if no zone is calling for heat then the oil boiler never really picks up any heat from the heat exchanger and the boiler could come on to keep the water in there up to the min temp... it does this all summer long ... but since one of my existing zones is for my domestic hot water that pump comes on a lot ... thus water will circulate through the exchanger. Also I assume some natural convection will happen. I am curiose if anyone has installed like this and is the oil burner comming on a mojor problem? It would seem that if it's cold enough for us to be running the OWB then one of the zones will be looking for heat and circulating the water! I really do not want to go through the expense of putting in another pump and making the instll more difficult!

there is no major problem for the boiler coming on,i feel that it is inefficient and a waste of fuel, but hell i am burning wood so i do not want or need to use that tin box.

 

[mga]

I have been reading the thread and post by Jeep ... basically my install was going to be very similar to his. 4 zones each with a pump ... only run when a zone calls for heat. I see the problem that if no zone is calling for heat then the oil boiler never really picks up any heat from the heat exchanger and the boiler could come on to keep the water in there up to the min temp... it does this all summer long ... but since one of my existing zones is for my domestic hot water that pump comes on a lot ... thus water will circulate through the exchanger. Also I assume some natural convection will happen. I am curiose if anyone has installed like this and is the oil burner comming on a mojor problem? It would seem that if it's cold enough for us to be running the OWB then one of the zones will be looking for heat and circulating the water! I really do not want to go through the expense of putting in another pump and making the instll more difficult!

how big is your house that you need 4 pumps?

my house is 2000 sq.ft and i have only one pump and two zones.

 

[sstan]

When we built (about 2200 sq ft) we decided on individual pumps for each sone (3 heat and one for hot water) instead of Zone valves. The thought being if one pump went bad then we would not be out of heat for a day (I know .. could have boughten an extra pump and put it on the shelf and use the zone valves ... just a choice at the time). So after reading all this I think I will plumb igt in without the Oil burner loop and extra pump .. see how often my oil burner kicks on .. I am counting on the hot water zone and natural convection to help avoid it kicking on too often but who knows ... next year I may have to change it!! I am still confused on which part of the existing loop I should install the heat exchanger in .. comming out of top of oil burner and going to zones or as they return and go to the pumps and then into the manifold back to the bottom of the oil burner ( assuming that is how the water flows and the pumps PULL water through the zones).

 

[jeeptj19992001]

sstan where are you in ny?

 

[mga]

boiler pumps should be on the return line.

i guess the reasoning behind this is so that the hot water directly from the boiler runs thru the system first before it hits the pump. something about helping the pump live longer......