bleeding baseboard hot water system

dalton

I have baseboard heating, why do i have to bleed via baseboard each season if its a closed loop system and what other maintenance i have to do for the up coming heating season.

DaveC

When the system is off for the summer...

the pressure is probably lower than during the heating season, even with an automatic feeder. Air can find it's way in, particularly if you have more than one story or older components or piping methods. You could install automatic air vents or have a pro check the system out. Every couple of years it's good to remove the baseboard covers and brush/vacuum the fins. The boiler should be serviced/combustion tested yearly, the extent depending on whether it's oil or gas fired. Hope this helps your inquiry.

dalton

Thanks Jim that was helpful. I'm in the business but my speciality is A/c, so i'm very handy. My home is in fact a 2 family,the piping system is a little antiquated, the boiler about 13yrs old, rated at 125k btu.(slant fin)for a 1150 sqft each floor, including the basement.Preliminary calculation says the boiler is undersize and i should be around 150-160k btu.This means that the boiler runs longer to heat the home and you can imagine my gas bills.I will change it next summer.My Q to u is (1)where do i install auto bleeders (2)I obviously bleed the system while its running (3)How important is cleaning the chimney. I know i have some bent fins which i will straighten-out and vacuum this weekend.

Mike T., Swampeast MO

If you can heat the place in the coldest weather I cannot think of a reason to increase your boiler capacity.

Nice, long firing times are the friend of efficiency, not the enemy!

DaveC

I'd agree with Mike...

The heat loss calculation may be over compensating for somethings, maybe your insulation or infiltration is not so bad? If the boiler has proven to maintain your inside temperature on the coldest days, there's no reason to increase the capacity. When you do change the boiler - you can stay with that input, but put in a higher efficiency one to get the fuel savings. Consider pump location - if the system can be configured with them on the supply (maybe read Dan's "Pumping Away" book) it might help your air problem.

If you're bleeding manual vents, start at the beginning of the loop, from the boiler supply, and work your way back to the last one on the return. Maybe your fill pressure could be increased a little (20 psi), but be cautious about getting too close to the reief valve setting (30 psi) when the water is at it's hottest. The air bleeders should now be located at the high points at the end of each run - if so, that's where the auto bleeders would go. Also one on the boiler supply pipe air scoop? If possible, the baseboard pipes should be pitched ever so slightly up toward these bleed points.

I guess you use oil? A chimney cleaning every 5 years should be adequate. Checking for the base to be clear each year would be great to do in between. Stainless steel cap with screen or just a screen is good protection against furry and feathery friends. Annual service and combustion check is essential, and worth the cost. Happy heating!

DaveC

One other thing to check,, Dalton...

The boiler's rating plate may state a certain input, but it could be actually running higher (or lower) than that number. Assuming it's oil, have the pump pressure and nozzle size confirmed. Overfiring the boiler will decrease efficiency. Slant/Fin offers oil fired boilers that allow a range of input rates. Consider an XL-2000 model 30, which could fire at 160,000 BTUH - but run the smaller nozzle size for 140,000 BTUH. Now you get the highest efficiency - with allowance to increase for whatever reason, if necessary. I like using an indirect water heater with this for your domestic water needs, which you probably have a high demand for.

If you have gas, the boiler should only be fired at the specified input rate. Definitely have that and the combustion confirmed - particularly if you suspect it is being overfired, which could be a severe hazard.

CO alarms are important to have - do a search here for the one(s) that really work and where to get them.

Now yer set, I believe!

dalton

> The boiler's rating plate may state a certain

> input, but it could be actually running higher

> (or lower) than that number. Assuming it's oil,

> have the pump pressure and nozzle size confirmed.

> Overfiring the boiler will decrease efficiency.

> Slant/Fin offers oil fired boilers that allow a

> range of input rates. Consider an XL-2000 model

> 30, which could fire at 160,000 BTUH - but run

> the smaller nozzle size for 140,000 BTUH. Now you

> get the highest efficiency - with allowance to

> increase for whatever reason, if necessary. I

> like using an indirect water heater with this for

> your domestic water needs, which you probably

> have a high demand for.

>

> If you have gas, the

> boiler should only be fired at the specified

> input rate. Definitely have that and the

> combustion confirmed - particularly if you

> suspect it is being overfired, which could be a

> severe hazard.

>

> CO alarms are important to have

> - do a search here for the one(s) that really

> work and where to get them.

>

> Now yer set, I

> believe!



Jim i neglect to tell u that it is a gas fired boiler. These are things i know i can do myself with some help.(1) how do i check if its overfiring (2)what other maintenance i can do.(3)I probably should get the chimney cleaned. I moved in a year ago and it hasn't been cleaned since.(4)I'm going to fire the boiler-up on Sat. I need to bleed each baseboard while running, right? I also have co alarms installed already.

DaveC

Dalton, actually you did mention...

your gas bill was high, and we don't offer a 125,000 BTUH input oil boiler - so I wasn't on the ball here.
I questioned the input rate because of the gas usage and the descrepency in the heating load vs. rating plate input. Do you have the instruction manual? I believe we have them available online or you could contact our Technical Service for this:

www.slantfin.com

(800) 873-4346

There are procedures in the manual for checking the input rate and cleaning the heat exchanger and burners. Getting a pro to check the combustion is recommended. Oil fired equipment requires more frequent chimney cleaning, but you might want the peace of mind in getting yours checked out, especially for deterioration or blockage. Bleed the radiators after the water is over 140* F.

You might also want to do a search here on the topic of CO detectors - there's been alot of discussion about brands, effectiveness, and location.

George_10

Has this system been cleaned and treated

If not, you should consider it as this will help increase the efficiency of the system and lower your fuel bills.

Check out our web site www.rhomarwater.com or give me a call at 800-543-5975 (George Hunt)

dalton

Jim if u get a chance check out my Question on automatic air vents 10/07.

DaveC

I'd go with Ken's advice...

but then again, what does he know?

(Just paraphrasing you, Ken)

Pump away, locate fill and tank correctly, spirovent at boiler, auto air vents on radiators - sound right?