Weil-Mclain Ultra piping question

MikeAR

Has anyone used a Weil-Mclain Ultra on a gravity conversion? All of their piping diagrams are for radiant or multiple zones using P/S piping. Is it really necessary to use primary/secondary piping on a single zone system when using a condensing boiler? There are no TRV's, or DHW in the system. I just don't see the advantage of it in this situation.

Thanks

Mike

Floyd_5

P/S is a must......

Mike, in this situation you will want to move the water slowly through the existing gravity piping. This will require that you install a pump that will only move the water slowly.... a Taco 007 MAX!!!!
The boiler will have a larger pump with it, depending on the size of the boiler..... This too must be sized closely to meet the need with out being grossly oversized.....
Install the closely spaced tee's to the boiler, in the gravity loop before the small pump, setup your reset, and away you go... it's really not any harder to do it right.
You will end up with a nice wide delta T on your supply and return and the Ultra will love the cool return temps.!!!!

Have FUN!!!!

Floyd

John Madden

W/M Ultra.

I think Floyd has steered you right. There is a wicked pressure drop through the Ultra. Using P/S and closley spacing tees a very small circulator on your secondary should do the trick. My only concern would be dirt from the old system getting back to the very small passages in the boiler. A "Spiro Dirt" might be a good idea. This unit would also add some resistance to your secondary loop, keeping flow rates down.

fstedy_2

W/M Gravity system

I installed an Ultra 160 in January of this year. Its installed in a converted gravity feed system in a 140 year old home and it works great. My heat bills dropped about 35% since January.

I used the Taco 007 that was supplied with the boiler and two other 007's one for the system and one for the DHW. The system was piped as per W/M specs.

I got it up and running about 2 days before the big cold snap here in the northeast ( Southern NJ.) and it kept my home at 70 degrees even with the High Temp. Limit set at 160 degrees. The only problem that I noticed was on the coldest days 5 - 10 degrees it was slow to recover after overnight setback, so I left the temp at 70 on the coldest days due to the recover time ( 3" parallel feed system in an unheated crawl space).

Hope this is a help to you.


fstedy