OK Heating Techs, Pyro Extraordinaires, and all who love this stuff, its Crunch Time... HELP

[trehugr]

The EKO 25 is ordered, the shed is moved so the excavator can dig and put gravel down for the concrete, the 80', 4' deep trench is half dug, the decision to use 1" PEX with foam in ditch has been made. Other decisions include piping the boilers in parallel, 500 gallon propane tank in the basement, Superstor 40 gallon indirect water heater and the 86 gallon expansion tank residing in the shed with the EKO.

I have read and read and read. There are several things I just can't seem to find answer's to. First and most importantly, will I have to change the pumps in my existing system to accommodate the additions ? I will be adding a baseboard zone in finished basement room. Where do I need to add pumps, or retro fit with zone valves, or change the size and location of the pumps? Trying to avoid expensive controllers, but will I still need one or more ?

Please pardon my poor Photoshop schematic. Looking for mistakes and comments on this system diagram. Will the intersection ( black cross ) work with the appropriate valves and check valves ? I really need some solid answer's to start ordering hardware.

 

[Nofossil]

Do the fossil boiler and the EKO have their own circs not shown in the diagram? You'll want to include check valves, mixing valves, and other goodies.

 

[trehugr]

The whole point of this post was to figure out what I need to change, or not and what needs to be added. I show the existing system (in gray), which has 2 zones with 2 taco 007 pumps on the return lines to the oil boiler.

Lets start with pumps, thats my biggest mystery up to this point. Im not trying to be vague, just a little desperate to nail down a basic plan for this system.

Kev

 

[Nofossil]

So this gets a little complicated. I was hoping some of the plumbing guys would jump in, but maybe they're waiting until I make a mistake.....

I assume that one of the goals is to make minimal changes to the existing plumbing. I don't see any way to avoid some changes, though.

I assume that the DHW is a SuperStor or other indirect DHW.

If you want to stay with a circulator for each zone, you'll have to add one for the Superstor. As far as I can figure it, you'll need a circulator for each boiler as well. I think the simplest geometry is something like the diagram below. The important idea is that there are clockwise loops. If you have an active boiler you have a clockwise loop that goes up through the active boiler and down through either the storage or the zones.

If you have a heat demand, you have a clockwise loop that goes down through the heat load and back up through either the storatge or the active boiler.

Boiler circs run whenever the boiler is hot.

Load circ (or circs - this shows one circ and several zone valves, but it could be a circ per zone like you have) runs whenever there's a heat demand. PM me - I'd be glad to explain by phone tomorrow night if that would help.

 

[Redox]

Kevin, calm down! You have all summer to weigh your options. Run the pipe and set the boiler; the rest are just minor details at this point.

Chris

 

[trehugr]

Wow, Im sorry if I got a little panicy. It seems there is so much to do with so little time to do it. I appologize. I just need to get it in my head how this is going to work

 

[renewablejohn]

trehugr

Might I suggest you also post your request on the UK navitron site. They are normally very helpful and may come up with a different solution.

 

[Jersey Bill]

It looks like you are forced to use the storage all the time, including when the fossil boiler is firing. Why would that be good?

 

[trehugr]

Can a taco 560 3 way zone valve be used to direct water to storage or to heat zones as needed ? Is it better to use zone valves on heat zones as opposed to circ pumps ? And if it is should the main pumps on the boilers be on the return or feed sides ?

 

[Nofossil]

It's almost a theological argument. If you have a relatively small number of zones, I think having a circulator for each heat source and a valve for each zone makes sense. Less power consumption, for one thing.

If you have a lot of zones (6 or more) or if you have zones with seriously different flow requirements, having a pump per zone gives you better control of flow rates in the zones at the expense of more electrical power consumption.

The simple schematic I posted above accomplishes routing to storage and zones as needed without a 3-way valve. In my never-so-humble opinion, simpler is better.

Purists would pump away from the boilers, but I don't think it makes too much difference in residential scale systems. I pump into my boilers with no problems.