1st mod/con. circulators/ zone valves?

plumber11248

I am installing my first mod-con boiler on Monday.  Installing TT prestige solo 175 with

Smart 50 indirect tank, two zones of baseboard and two future zones. Piping primary/secondary.  Trying to decide to zone with circulators or zone valves?

Any thoughts on piping/ zoning?

Big Ed_4

Depends

What type and size zones ?

plumber11248

baseboard.

existing zones are baseboard, aprrox 85' each. two furure zones are unknown and are only going to be tappings with isolation valves for now.

Big Ed_4

Loops

Large Loops and your extra large loops, I would use circulators ...

CMadatMe

Why Such a Big Boiler?

Zone with zone valves and use a Grundfos Alpha as your system side pump. The question I have is why such a big boiler? 85 feet of residential baseboard per zone even at a 4GPM flow rate is only 102,000 max output at 180 degree water. I also wouldn't primary/secondary.  I would use a hydro seperator/low loss header. While primary/secondary will work, keep in mind it was primarly developed to protect cast iron boilers from being shocked. A mod con prefers to have the coldest water possible returning from the system to get it's best efficiency.  One of the beefs I have with most mod/con installation manuals is that they don't even offer it in their piping arrangements which is a shame. It isloates the boiler from the system side , collects any debris plus helps in promoting condensing.

plumber11248

LARGE BOILER

Chris to your question why so big.  Customer is expecting to add an two floor addition of unknown size and has asked that i provide some capasity for the future. I figured with the turndown abilitys of this boiler this would be a safe bet.  The hydro seperator/low loss header sounds great, don't know how expensive they are, but dont have it factored in to my cost, things i will have to think about for the next one.  Any control of choice for the zone circulators?

EricAune

Circ relay

Simple, Taco makes a great line of relays for circulators.  SR503, 4, 5, 6 depending on how many zones you will end up with.  Each will have a priority zone designation if you have DHW.  These relays will keep it as simple as it gets.  

CMadatMe

Zone Control

I had to edit my original post meant to write zone with zone valves but after reading your follow up post I would zone circs knowing that a possible 2 floor addition is being used.  With the possible addition I can understand the increase in boiler size.

bob eck

circulators

check out using grungfos ups1558fc three speed circulators with built in check valves for secondary pumps check with triangle tube for what circulator to use going through the boiler heat exchanger also use a grundfos circulator for the indirect water heater.

plumber11248

MY ORIGINAL TOUGHS

My local tt rep. is specing taco 0010's for primary and dhw and two 007 for seconadary basboard loops.

Was just looking at the grunfos alpha, looks like a great pump for the primary and dhw. almost same cost.

Was originally thinking zoning with zone valves, and just installing a r832a circulator control for single taco 007 secondary pump. Dhw priority would be controled by boiler control, shutting down the primary circulator when there was a call for hot water.

Was thinking this would be the simplest solutions, and would eliminate , 1 circulator, and four flow controls on the two secondary loops.

Still needing flow controls on primary and dhw loop.

Does this seem sound?