aquastat setting

pat_3

what is the highest (safe )aquastat setting for a residential hot water boiler?thank you in advance for any replies

Larry_10

it depends on your boiler and what it can handle. but in most cases it all depends on what your heating your house with if your using radiant then it would be low if your using baseboards it depends on what your baseboards where sized to run at for your house load

good luck

pat_3

the heating system is all baseboard...i replaced the boiler 3 months ago ,now when the temp goes below 20 the first floor will not maintain higher than 68 .pretty old house,sized the boiler by measuring existing radiation,boiler reaches high limit190 and cycles as it should.customer says this never happened before.the only thing i can figure(if in fact this really never happened before)is that the old boiler was running at a higher aquastat setting?

todd s

Existing system

Was this originally a gravity system converted to pumped?

pat_3

no.it was not a converted gravity system.

M Ransley

Did you bleed each radiator individualy of air while the system was running and keep proper pressure? Is Aquastat correct, get am IR theromoeter 30$ Radioshack with 3f +- accuracy and hit the output water pipes, If system is under @ 15lb pressure water does not boil at 15lb till 248f, up it to 200 and check stat temp

pat_3

system was purged properly,temp was tested for acuracy,bumped it to 200 about aweek ago ,i think it made a difference but i dont live in the house,so i only know that it won't maintain temp when outside temp gets around 10.how high can the aquastat be set before it would be considered potentially dangerous.(i would assume not beyond 212,just in case there was a sudden drop in pressure the water wouldn't flash to steam,but 90%of our work is new or complete system change,i've seen alot of boilers jacked up to 220 but i won't do it unless i'm convinced its safe)thank you in advance for any replies.

Weezbo

dont be Lazy ...go back over there....

and get( a ) . a new zone that applies heat to each room to offset the lack of properly sized heat emmiters according to your heat loss..(b )..remodel every zone to main tain temp at 70 at designe degree day . cranking up the heat higher and higher really shouldnt be the stradgey , nor should adding more and bigger Pumps. thats my story an i'm stickin toit.

pat_3

laziness isnt the problem,the job was a boiler change out,i'm just trying to figure out what could of been different with the old boiler that would have made it maintain temp .then addional work can be done to fix what i believe was already an existing problem (whether the homeowner realized it or not).right now i have customers that think i created the problem....i think i discovered an existing one.if the aquastat raised to a higher safe setting can maintain ,then it will be up to the customer if they want to correct in another manner.

pat_3

weezbo

> what is the highest (safe )aquastat setting for a

> residential hot water boiler?thank you in advance

> for any replies



i hope the customer gets an opinion from another contractor like you.i just want them to understand it wasn't created when we put in the new boiler(the new boiler was sized not by a heat loss,but by measuring the existing base board which was said to heat the house fine)

pat_3

weezbo

i hope the customer gets an opinion from another contractor like you.i just want them to understand it wasn't created when we put in the new boiler(the new boiler was sized not by a heat loss,but by measuring the existing base board which was said to heat the house fine)

pat_3

weezbo

i hope the customer gets another opinion from a contractor like you.i just want them to realize the new boiler isn't the problem and that the problem aleady existed.

Weezbo

i went on two freeze ups today...

oh buddy you dont want to be playing games in 30 40 below. Nope. it never is as simple as you are led to belive...marrying the building because "you" fixed a 90 aint in my vocabulary.

pat_3

you lost me?

Weezbo

i savey now...you stick to your guns,The BTU'S are available

it isnt on You in your mind and the homeowners well...they are probably thinking.."it was all working Great before You fixed it!"to explaine that the other boiler was doing this or that is meaningless,heres why you listen to Fire Dragon, Take reading when you Get there ......and before you leave. is that always going to answer the problem..no buh it sure lets the home owners know you are aware of what it was or wasnt doing and can Prove it. sometimes the older blast furnace was plenty able to turn the iron into a heap of slag if it had to if you have no lee way on the emitters then you have to match theflow rate and temp of the previous system.if it is working as you suggest what happens if it really does get cold? put a bigger pump and higher temp? i would fix it say to myself 'aint doin that again' and having paid for the experience 'wont soon forget it' might be the other companion thought with it. the school of hard knocks is a toughie...books and science may seem like a waste buh really they can help you alot.that isnt to disparage you or demean you in any way, i prefer to run my boiler temps and field temps lower with by passes and a bit extra heat emmitters. if the field was sufficent in my walk through i mention that the previous system wasnt about saving money or fuel and that at This time here are some of my sugestions,....if they are undersized i look at the boiler and say ok, this is running at such and such a pressure and temp. oH hey! it has a 50 psi relife! oh .. hmmmm.....minor technicality..... really while it may be that you feel it isnt your fault it is your responsibility.......on to another topic...i have had to make things work because i was called to do so in temperatures you have likely never even heard of ...the boiler itself is losing against the cold,i did what i could over the telephone,now i have to do a bunch ofpencil pushing and figure out specifics of the boiler fire box ,return temps and pressure and flow flue size and bust out a group of tools and instruments to help them out of the "woods"....so am i happy to run boilers into the 200's well no buh it indeed can be done.is 212 too high? no.it has no place to go,if it cant escape its in there. 220 i hate to do it buh like it has been stated as long as the temerature is being controlled from over running the control and pressure you are safe. thing is i have had people turn the boiler high limit into a joke,i show up and it is over 300 degrees whews it is a scary deal, they have large unit heaters blowing air through them 90 to nothing to hold against the cold so they can work in the place and get the vapor barrier installed...in other words things that i really wouldnt recommend doing, i have seen functioning....some things the boiler manufacturers wouldnt recommend well i was called to do that for people also,here is where i say a sharp pencil and accurate measurements become one best friend. some things that would help someone are not far from something that could cause them a LOT of grief...it is better to take the way of the well trodden path on some issues....in your case,explaining isnt going to solve anything and excuses wont make it either..you want to be a responsible business man and do good quality work long into the future in your community so, be responsible. pumping the water temp up also is going to buy you 50 btus a foot basically for every ten degrees higher you crank the temps....on heavy type iron baseboard,.. once you start out of 230 degree range well, you best be having that in writing somewhere. like i said earlier i am uncomfortable having to do things that i dont like to do....however no ones ever had to DIE over it.

Rich Wurzbach

IR thermometer

Be careful with the use of an IR thermometer. On a new installation with shiny copper pipes, for example, the non-contact thermometer will give a reading significantly lower that the actual temperature, because of something called emissivity. You will get a reflection of the temperature behind you, which is much lower than the pipe temperature. These are much more accurate on dirty, painted, or corroded metal surfaces. If not sure, use a piece of black vinyl electrical tape on the surface, let it warm up to pipe temperature, and then take the reading right on the tape.