Mikey,

You mention homerun system and I hope you dont mean with the plumbing manifolds.

If you want to bring all the supplies back to one source, use radiant heat manifolds with circuit setters (flow controls). Otherwise look into 2-pipe reverse return hydronic piping systems. Either way, it is crucial to balance flow to each TRV.

1 thing to remember when selecting the circs, ht x and piping.

1GPM can carry 10,000 BTU's

36,000 BTU's is not alot of load, Your circs shall be small, I would consider the Grundfos or Taco multi-speed and, of course the circ on the water heater side of ht x must be bronze or SS.

Go with the smallest ht ex they have with 1" connections. Assuming all panels are calling, you may want 1-1.5GPM per run.
With that and 1" between htr and ex your exchange and Delta will all fall in line while maintaining pump efficiency.

zl700 - thanks for the detailed reply.

I was/am planning on using copper manifolds with just ball valves on the return for isolation. I was told by veha that I can balance the flow with the valves on the radiators. Is this not the case? I may have to rethink my manifolds.

I am planning using a multi-speed taco pump (00R - up to 18 GPM on High) for the radiator side.

I am having problems finding multi-speed pumps in bronze for the water heater side. Should I look at one like the taco 006 (10GPM) or upsize to something bigger like the 007 (20 GPM). I am guessing there is not much head loss on the water heater-heat exchanger loop???

Can I get away with a heat exchanger with 3/4" connections. The 5"x12" 3/4" connector claim 20 GPM and are much less expensive than the 1" connectors.

again thanks for the direction.

The bronze pump between the htr and ht exch is actually considered to be on an open system so, the circ curves you are looking at are not applicable. But, for the most part, when not drawing hot water it becomes closed, to a point.

I'm sure you will get by with the 3/4" tappings assuming piping is kept short; being that the ht exch is close to the htr. By not going 1" the pump curve rides higher but with only 2 pumps on the whole system, the energy waste is slightly negligible.

If the piping is short, chances are the 006 will be closer to 15GPM.

The TRV's donÂt balance but as they are satisfied and start closing water will then take the path of next least resistance. If it is not important to have a balance system on cold startups, I wouldnÂt worry about it.

I am assuming that you will be using a central stat to activate both pumps via a circ relay that are wired in parallel with each other?

zl - i owe you a cold one. thanks again!

All the pumps and controls will literally be right next to the water heater.

I understand that the trv's do not balance. But what about the angle valves on the other side? Do the trv's go on the supply or return side of the radiator?

I still have not figured out how i want the system to activate. The radiators will be for a background type heat, bringing the house up to a tolerable level. We will use our wood stove and ample supply of wood (we live in the forest) to do the majority of the heating. I know the trv's will be nice since we can still supply heat to back rooms that will not benefit from the wood stove as much, but not overheat those areas that do benefit from the stove. We have thought about a thermostat in the coldest room, an on/off switch, or even a thermostat outside??? Ideas?

We have thought about adding a mixing valve with outdoor reset, but the wife wants it as simple and as cheap as possible at the moment. I have been told i can add the mixing valve and outdoor reset easily at a later date.

The TRV's should go on the supply/inlet side of panel. They are designed to sense ambient air and shouldnÂt be fooled by preheating radiator before reaching the other side with the valve.

If you are getting the angle outlets with the adj metering orifice you could balance somewhat. Best done at cold startup and valves cranked to the hottest setting and you running around with an infrared thermometer, or you hand if you can think you will get close. If you went with the radiant manifolds with flow meters, it would be a piece of cake. Otherwise you can balance at the manifold with your ball valves if trimmed out with SS guts.

An outdoor stat could work but since you are not resetting the water temps with outside, perhaps put the stat to enable the heating in the coldest area of house least heated by the wood and let the TRVÂs take over. Should the heat be enabled yet all TRVÂs are satisfied you would be wasting energy at pump and deadheading. That is why in your simple system I would go with indoor stat, 1-2 degrees higher than TRV setting and consider putting a small ½" adjustable bypass between htg supply and return to solve possible pump deadheading.

I like the authentic German Hefe-weisens (IÂm going for some with wiener schnitzel today at lunch)

When it comes time to add the reset feature, a mix pump with built-in control would be your best and easiest set-up/install.

See below:

Here is a link that might be useful: Grundfos miximizer

good point on the TRV's on the supply side.

I have looked into getting the radiant manifolds. It is a high price, well over double, for just having simpler balancing. My plan was using the adj metering orifice (valve) on the angle outlets and using a infrared thermo. I was also thinking of using the ball valves on the return side of the copper manifold. I will have to look into more and make a decision.

I think I will put an indoor thermostat in one of the cooler rooms. I will be using a bypass valve to prevent deadheading.

Hefe-weisens are nice. I am an IPA fan. I like the hops. I brew my own and have not tried Hefe's. I may have to give it a go.

You will be all set
I too brew up to 5 galls at a time

zl700 - thank you once again for all of your help. i must say, in all my posts and questions, your response has been one of the most helpful. I will raise a cold one in your honor tonight.