Harman VF 3000 installation and set up tips

i've got a fwh boiler with 4 zones and a oil fired hot water heater.

i have the hot water coil for the vf which i plan on hooking up with a hot water tempering valve and shuting off the oil fired hot water heater untill it gets warm.

i was going to hook up the vf in parallel with the fwh boiler and leave the circulator pump on 24-7.

i'll set the fwh boilers set points far enough below the vf's so that the only time it should ever come on is if the vf goes out.

is there anything i should do different?

my house is around 2500 sq ft, new windows, not the greatest insulation and a wood burner running in the cellar 24-7 until it gets warm.

i hope to have it up and running by the end of the day.

let me know
thanks
jim

My only suggestion would be to take the domestic water from the vf coil and dump into the oil water heater. You can do a valve bypass. Then you have the option of using either or both easily. Then you're also using the oil water heater as a storage tank and it should only fire to maintain temp, never to bring cold water to temp.

coalkirk wrote:My only suggestion would be to take the domestic water from the vf coil and dump into the oil water heater. You can do a valve bypass. Then you have the option of using either or both easily. Then you're also using the oil water heater as a storage tank and it should only fire to maintain temp, never to bring cold water to temp.

she's up and running!

thanks. for now i'm going to run my cold water through the hot water heater first and use the tank to bring the water up too room temp before i run it into the hw coil.

later i want to get it all hooked up with a solar hot water heater tank/system i have.

maybe i'll get that all hooked up before the spring and burn even less oil.

jim

awesome, congrats!!! got pics?

Hello sandman, I'm confused about your proposed routing of cold domestic water through the heaters... You said you were going to route cold water into the oil heater to bring it up to room temperature, then through the coil in the coal boiler.... So are you going to use oil heat to raise the cold water to room temp or are you hopeing the water will stay in the tank long enough that it will warm to room temp without useing the oil heater??

The Heater tank is insulated, so I don't think you will get much if any rise in the water temp in the tank without using the oil heater, and this defeats the purpose of the coil in the coal boiler.

I would route cold water through the coil first, then store this water in the oil fired hot water tank. The oil burner will only run to maintain the water temp, and this will only be after long periods of no hot water use. The water from the coal boiler coil will be 150*+ and the oil hot water heater is probably set at around 115*-120*. So the water can cool for many hours before needing to be warmed up to the 115* setting of the oil burner.

This is similar to the setup I have for my domestic hot water. My cold water goes through a coal heated water/water heat exchanger, preheating the water to 180* before it gets into the propane water heater. The water can stay there for most of a day without needing reheating... I periodicly run the hot water to bring in more [very hot] water into the tank to prevent the propane burner from ever firing. Before bed, I usually run several gallons of hot water to really heat the tank up for the night.. I also turned down the temp setting on the propane thermostat.. I use virtually zero propane for domestic hot water... Only if the house is vacant for several days, then just to maintain a low temp in the water tank.

You could install a small circulator pump to circulate the water from the coil to the tank and back, keeping the water at a high temp... You should plan on installing a tempering valve to prevent scalding... the water is very hot.

Congrats on the install, it's a great feeling to not hear the oil burner [propane for me] kick on and suck up all that expensive fuel !!

Greg

LsFarm wrote:Hello sandman, I'm confused about your proposed routing of cold domestic water through the heaters... You said you were going to route cold water into the oil heater to bring it up to room temperature, then through the coil in the coal boiler.... So are you going to use oil heat to raise the cold water to room temp or are you hopeing the water will stay in the tank long enough that it will warm to room temp without useing the oil heater??

The Heater tank is insulated, so I don't think you will get much if any rise in the water temp in the tank without using the oil heater, and this defeats the purpose of the coil in the coal boiler.

Greg

thats how iv'e got it set up, if i put my hand on the water coming into the oil fired water tank it's quite a bit colder than whats coming out.

even if it helps just a little i'll be happy and it will keep the water moving in the heater.

i have no interest in firing up the oil hw unless theres a problem with the coal boiler.

thanks for the input.

jim

This poses a good question.

I have an indirect water heater that's basically a zone on my heating system. With a cold start oil fired boiler the oil only fires when there is a call for heat.

Now in the summertime the only call for heat is the hot water storage tank but a coal fired boiler has to keep a small fire going at all times. Would I be better off using the hot water coil in a boiler? Or just continue to use the indirect like I have it?

hmmmmmmmmmmmmm

Your indirect water heater will heat and store a lot of hot water, the boiler doesnt have that much water in it, so will tend to cool down faster and have greater swings in temperature when you use domestic hot water. I'd use the insulated indirect water heater/hot water storage.

If it isn't a lot of work you could try it for a few months one way, then try the other, and see which one uses less coal, and has more consistant hot water..

Greg L

well, i'm glad i didn't put a tempering valve in.

with the boiler at 145 the water's cooler than what i'me used too getting from the oil fired hot water heater.

jim

LsFarm wrote:Your indirect water heater will heat and store a lot of hot water, the boiler doesnt have that much water in it, so will tend to cool down faster and have greater swings in temperature when you use domestic hot water. I'd use the insulated indirect water heater/hot water storage.

If it isn't a lot of work you could try it for a few months one way, then try the other, and see which one uses less coal, and has more consistant hot water..

Greg L

OK, yah good point. I don't think it would be too much woork to plumb it nup so I can easily switch from one method to the other. As matthaus would say, "sounds like a good science project"

Hi sandman, your comment is sort of what I was getting at about putting the insulated storage tank after the domestic coil in the boiler. When you use a lot of hot water, say a shower and the dishwasher or laundry at the same time, you will probably find that the high flow rate through the domestic coil reduces the heat rise in the water to a [possibly] too cool temperature.
If you set up your domestic coil to circulate through the storage tank [oil water heater turned off] then the coil can heat and store lots of hot water, and the limitations of the domestic coil won't be a problem. It takes a lot of coil area, and a lot of temperature differential to make unlimited hot domestic water.

So if the cooler domestic water becomes a problem, you can raise the water temp in the boiler by 20*, this will help, or you can replumb it with a small circulator to keep the storage tank full of full temp hot water. Nice to have lots of options.

Greg L

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beatle78 wrote:This poses a good question.

I have an indirect water heater that's basically a zone on my heating system. With a cold start oil fired boiler the oil only fires when there is a call for heat.

Now in the summertime the only call for heat is the hot water storage tank but a coal fired boiler has to keep a small fire going at all times. Would I be better off using the hot water coil in a boiler? Or just continue to use the indirect like I have it?

hmmmmmmmmmmmmm

I've got an indirect hot water heater that can be heated with coal or oil boilers. Last summer I used oil exclusively and had a running time meter on my oil burner. Knowing exactly my oil consumption showed me it cost about $3 a day to heat domestic hot water. This summer I plan to burn coal. It will be much cheaper even though a lot of the boiler heat will be wasted by direct radiation. My boilers are not in my home so I'm not air conditioning that lost heat.

Yanche wrote:

beatle78 wrote:This poses a good question.

I have an indirect water heater that's basically a zone on my heating system. With a cold start oil fired boiler the oil only fires when there is a call for heat.

Now in the summertime the only call for heat is the hot water storage tank but a coal fired boiler has to keep a small fire going at all times. Would I be better off using the hot water coil in a boiler? Or just continue to use the indirect like I have it?

hmmmmmmmmmmmmm

I've got an indirect hot water heater that can be heated with coal or oil boilers. Last summer I used oil exclusively and had a running time meter on my oil burner. Knowing exactly my oil consumption showed me it cost about $3 a day to heat domestic hot water. This summer I plan to burn coal. It will be much cheaper even though a lot of the boiler heat will be wasted by direct radiation. My boilers are not in my home so I'm not air conditioning that lost heat.

Yanche, I will be curious as to how much coal you will burn per day this summer.

Each day in the summer our family has the following hot water needs:

1. 2 showers (will be 4 in several years)
2. Dishwasher
3. Laundry (warm/Cold cycle)
4. General sink use for rinsing washing hands, dishes, ect.

I think an hour meter is a good idea!

Sooooo care to enlighten me as to what kind of hour meter you are talking about? I know it will run off the power to the burner, but any details you can give me would be much appreciated.