Weil Mclain 468 V without a hot water heat exchanger

Alsea

Hi Guys ......  I wish to use this older non condensing oil fired 468 V to heat my 1100sq. ft home using pex tubing divided into 5 zones and using just the one curculator pump to drive the 5 zones at once......

The problem I have is that the boiler likes it it 140 F or better and while the pex tubing is rated at a higher temp I only want the floor which is imbeded in a  1.5" gypsum overlay to run no more than 90 deg..

I have seen  mixing valves but I don't see how they work, if the boiler is full and you add cooler water then where does the extra water go....??

it would make more sense to take that water from the return line to thin down the 140 F but even at at a 20 deg drop the water would still be 120F....

Or am I really stupid and you would actually run the boiler at a water temp of 80F ....

 

What am I missing here....??



Thanks

Peter

kcopp

its all in....

the piping.   http://www.taco-hvac.com/uploads/FileLibrary/5000MixValve(PA07).pdf



You need 2 circulators. 1 for the boiler loop,1 for the radiant loop.

SWEI

Better yet

an iSeries-R http://flopro.taco-hvac.com/products/index.html?category=188

icesailor

I Series:

Use the 4-way "I" Series with the ODR, it's idiot proof. It maintains boiler water temperature and the zone will maintain at anything you want. Works wonderfully on old houses with big cast iron radiators.

Probably the most cost effective update you can make to an old gravity or converted forced system which will stop old cast iron boilers from croaking from condensation.



Usually on an old system, an additional, well placed pump is all you need.



IMO.