taco fuel mizer

keith_27

Has anybody here had any problems with Fuel mizer relay. ????

Dave H_2

FuelMizer Relay

Keith,



Why do you ask, are you?



Dave H

keith_27

taco fuelmiser

had one i installed this summer. Homeowner said it was not working turns out it was a thermostat that the setback was to wide. Its also been very cold around here.

Dave H_2

Deep setback

Deep thermostat setback and an outdoor reset controlling the supply water temperature to the heat emitters can make homeowners think something's not working.

The response time to get the house warm again can take longer especially when you hit a cold snap like this one (45 degrees during the day, 5 that night).



Glad all is OK



Dave H.

archibald tuttle

difference between american and european heating philosophy

aggressive reset with a fuelmizer (never used one but used the PC 700 and 702 which are plug in versions for the 50[x] exp series) is not compatible with typical aggressive thermostat setbacks. 



The simplest version if you want to retain the extent of reset defined largely by the parameters of boiler and outdoor design temp, is to anticipate the setups by a number of hours to target the acheived temperature for the desired time.you can also game the reset control by monkeying with the outdoor design temp.  just raise that outdoor design temp and the curves of temp. provided go up. although obviously this reduces the benefits acheived by reset because that will happen globally and not just during make up periods. 



i suppose if someone was clever, now that i think of it, if you have 3 wires running to your thermostat location and used battery thermostats -- or 4 wires if you wanted to use 24V Common run thermostats, you could use two thermostats on a 503 exp (or any number above that with priority) style relay (don't know if they make a 503-OR or not, in which case you'd need a PC-700 to go with.) and then hook the setup thermostat to the priority call. little bit clunky but then you get reset at all other times (assuming when you are not in recovery, you set the priority tied stat to well below conditioned space temp).  this would require stacking a bit if you have domestic hw on the priority currently.  again, TACO could facilitate by providing more than one priority circuit.



i actually just got off the phone with Dave Sweet at TACVO regarding these and other features for future reset controls. which doesn't prove they think i'm something, just that i have their phone number and they know if they don't take my calls i'll come down and bother them in person, being a rhode island local.



the biggest problem i have with setback when we get into record cold -- well subdesign temps (from a control standpoint) compared to many of the systems that i maintain is when the thermostat goes into setback mode the system sits idle too long and the loops freeze at cold points that weren't taken into account by many early baseboard installers who just figured you'd be pumping the heat to it most of the time.while you can make the case here for constant circulation - more euorpean style -- see my subtitle - a more american solution would be for their reset relays that have an outdoor temperature input provide a setpoint which you could adjust based on the particular installation that makes sure pumps cycle once an hour (or maybe at a setable frequentcy between 1/2 hour and 2 hours)  if they have not been called by the thermostat if the temp. is below whatever freeze threshold you have input.  Never have problems with this stuff in most places until it gets into low single digits overnight, and then i'm running around thawing systems like crazy.  i remember the one where they ran one of the pipes in an unheated crawlspace. you've all probably all seen some variation on this.i would prefer they add a second boiler sensor, then you would generally be able to tell the loop has circulated if you had a feed and return temp sensor.  It would give an off signal for the hourly cycle and the heat is not wasted as it puts a small cycle of heat into the conditioned space without signifcantly elevating temperatures. 



In a way this could also provide delta T with a delta T pump, maybe they wouldn't be so into that but if you have a multiple pump system you don't always want to replumb the whole thing to zone valves plus new pump or replace all the pumps so this could bring some delta T control electronically.the slow recovery which we guess is your problem is just another an issue that could be easily resolved by added a conditioned space sensor and place setback (using setback hear to mean cooler temps. during day when out at work and at night when in bed) the programing control integral to the reset unit. there has been a move towards various brainy thermostats that integrate with boiler controllers on this.



the advantage to moving the setback to the boiler controller is that you can use virtually any existing 2-wire thermostat lead for a sensor but you have to rewire for brainy thermostat stuff.  then you could always add wifi and move the controls to the living space for convenience but these tend to be set it and forget it controls despite their theoretical convenience of being in the conditioned space. most folks don't look at them until something is already wrong in which case locating with the boiler isn't such a bad idea. not to mention it gives the boiler maintainer a really easy ability to toggle the thermostat and controls and monitor results rather than running up and down stairs (not that i can't use the exercise).



when the functions are integrated, the boiler controller knows that it just got a pickup command and it can provide hotter water until it sees a rate of rise in the space commensurate with recovery from the setback.this problem reveals that we are getting a lot of heating hardware and software directly from europe but it does not necessarily integrate with existing american heating systems and strategies and that is not changed just by putting in modulating boiler or pumping. 



you'd be well advised to more completely retrofit insulation, heating plant, heating element etc. to really embrace the european idea which does not engage setbacks -- familiar to americans from their thermostats going back to even to analog versions from before the first oil shortage that turned the heat up or down a couple times a day. Rather european strategy aims for parsimony with a constant space comfort.Most baseboard systems - what i see prevalently, were not designed for signifcant btu transfer at lower water temps. you could still make a baseboard system work this way and actually, come to think of it -  if they just added a time function on the reset controls, you could program different resets for different times of day the same as you have setbacks.  I doubt that would be particularly difficut and would be largely a software design issue without adding additional sensors - although i dig the functionality and logging info you could theoretically acheive with the additional sensors myself.



Because of the difference in old world and new world heating approaches a number of industry participants are engaged in trying to educate legislators that importing european standards for energy consumption at all levels, e.g. pumps, valves, controls as well as boiler btus is not particularly appropriate for much existing infrastructure. Of course i don't believe government standards for that kind of stuff are appropriate period, but i think the industry is taking a more (perhaps too) circumspect approach.



It is the very integration of advances in technology as they may be beneficially applied incrementally in exsting settings that poses the best possibility for consumers balancing comfort and cost. If new equipment appears less functional (as the fuelmizer does here, for instance in this circumstance) they will not be as widely adopted. people will cling to their old equipment like they did their 5 gallon flush toilers - not irrationally but out of seeing instances where the new stuff appears not to work.



Yeah we can be smarter about communicating and setup, but if we essentially raise the threshold where consumers can't get incremental gains but have to replace a larger swath of controls and equipment for any upgrade that discourages some. 



This isn't to say that european ideas are bad or doomed to fail here - people can understand dollars and cents and might go for more radical departure from the american norm at high upfront cost if they can document saving in dollars, comfort, maintenance, etc..



I'm running a half a dozen warm floors on poly butyl from the days before it was chichi.

Actually came on the wall today to find out where the heck i can get parts for a spirovent from the european days 25 years ago that is on one of those systems.  of course there is a bit more corrosion in the days before oxygen diffusion barriers and although most of the system is plastic or at least brass and copper, expansion tanks (and i was too cheap to use brass circulators at the time although they've come down since) pluse a cast iron heat exchanger provided plenty of galvanic action and the vent is that nice conjuction of air and water that takes some of the abuse meted out.



But you'd think that a 5 lb brass bodied vent, folks would keep parts around.  i cant get steam vent parts for vents that went in 70 years ago.  the spirovent people instead look at me cross eyed, like what is wrong with me for wanting to fix a 25 year old vent. That's service for you - or lack thereof.  I guess I'll have to write to europe to see if anybody has parts.  That to me is not the best of american attitudes. so i try to see both sides.



well, anyway, [more than] nuff said and if there was anything helpful it was in the first couple paragraphs and if there was anything hurtful i'm sorry as usual for being opinionated and longwinded but at least i don't hide my deficiencies.



brian