Taco Circulator

lchmb

I have a customer who recently had a condensing boiler installed in replacement of an old oil boiler. His only complaint is his bedroom. Which of course is the longest run. He state's it is never warm enough for his likings. Heat loss show's the room has almost 1.5 times the amount of radiation needed. The house itself has 7 zones controlled by Taco zone valves. My thought was to get the VT2218 to increase the speed to the zone on a call and hopefully put more heat on the far end of the house. My only question since I've never used this circulator is whether it will get confused in any way as more zone's open or close and will it effect the remainder of the house?

Leon82

The vt1816 has a constant and proportional pressure mode

lchmb

I was just thinking using the delta t feature who give me a more accurate temp drop across the system. The bedroom is center of the loop (which is poorly done and cannot be fixed). I did want to remove some fin from one area to cool the area of the t-stat til the bedroom satisfied but the customer didnt like this idea...was afraid he would get cold in another section...This is a viesmann boiler and we have gone "last resort" in changing the heating curve..This gentleman should never have been sold a condensing boiler..he doesn't understand it or want to live "with savings"...he wants it hot the minute he turns it on...

Ironman

If the Viessman is limiting the SWT to 167* max and the old boiler banged off at 180* or more, then that might be your issue.

Instead of removing fin tube, try closing the damper on the ones nearest the t'stat.

One of the biggest issues that can arise with high efficiency equipment is the failure to educate the customer on how it will perform differently from the old equipment. But, he should be more comfortable with a properly adjusted ODR than with the old bang bang setup.

Ironman

lchmb said:

This gentleman should never have been sold a condensing boiler..he doesn't understand it or want to live "with savings"...he wants it hot the minute he turns it on...

I don't know of any form of residential radiant heat that will do that. And his old boiler wouldn't do it either.

BobC

Can you just cover the fins to stop convection? That would let you demonstarte why you cant to get rid of fins in some areas.

Bob

Alan (California Radiant) Forbes

Kind of a waste, but in the interest of keeping the guy warm, set up the Viessmann to operate at 167° all of the time.

lchmb

ironman his old boiler was set to maintain temperature and when the zone clicked on he heard the tick tick tick of heat. I think I will try and cover some of the existing baseboard in the area of the t-stat and see if this will help. I did shrink the curve to a very minor amount and may just set it to 167 and let it go..sadly I think he can still hear the difference from 180..or least he thinks he can.
As far as educating, I honestly think that 90% of most older (lets say 65, dont shoot me) who have never heard of a condensing boiler should never be sold one...I personally will not. I dont believe they will see a return on their investment..

Leon82

I bought my house from the estate of an old guy. He had the boiler set to 195. When I had it cleaned a few years ago the guy dropped it to 180 and asked me if I set it that high.

Ill bet he has his tstat set to 75 or 80

Joe Mattiello

The VT 2218 offers 5 operating modes:
 Delta-T - variable speed, maintains constant ΔT, provides exact GPM flow required
 Constant Speed - 4 fixed speeds, maintains constant flow for zoning
 Set Point Heat - variable speed with boiler protection option, decreases speed on temperature rise
 Set Point Cool - variable speed, increases speed on temperature rise
 Boiler Protection - protects boiler from low return temperature and flue gas condensation
Is the pump sized correctly? I’m not sure which pump was used with the oil fired non condensing boiler. You can close the other 6 zones, and run the pump at constant speed to see if the pump has enough capacity to overcome the total dynamic head of the zone. That is actually the one most important for sizing the pump.
If you’re operating in the delta T mode, is the return temperature within 20 degrees of supply?
Speed 4 curve shows 6 gpm @ 14 ft head, so it should be ok. let me know how you make out. If you like you can call me direct at taco 4019428000

lchmb

Thank you Joe..I'm planning to get back there this week. I'm planning to run it on Delta t to see if it does what I hope..I'll give a ring if I run into any problems..
It's no wonder I use Taco for everything..you guys are second to none...One quick question though, do you know when your summer training schedule will be coming out? I have some tech's I'd like to get down for your 2 day training...
Thanks!!