I have a hot water system, fired by gas. The 3 upstairs bedrooms and 2 baths are on 1 zone., and it is a long run, about 150 ft total. The problem is the last two rooms on the run ( master bedroom and master bath) are much colder than the three that precede. Is the run too long? Do I need a bigger recirculating pump? Or should in opt to make another zone of the master bed and bath. Would low water in the system cause this problem? House is 6 years old.
Edited 1/11/2007 4:27 pm ET by paperhanger
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A loop of PEX in a hydronic system should be not more than 250'. It doesn't sound like your run is only 150' because it's serving all those rooms. What is the tube spacing on center, and how many square feet are we talking about?
Dave the sq ft of area is approx 1200 sq ft. The tubing is 3/4 inch copper and is a fin type baseboard. The total length of run is closer to 200 ft boiler to boiler.
For some reason I thought you were talking about radiant floor. Obviously not.
If you have fin tube, is furnture/curtains blocking the raditors? Are the dampners closed down on the raditors" Is carpet blocking the air flow from underneath? Have these rooms always been cold? Could be a lot of things. The rule of thumb for length of fintube on a zone combined is 75'. Piping dosen't come in to play as much, it's the total lenght of all fintube on that zone. Are you zoning with circulators or zone valves, are they working propertly? Has the system been bled of air?
Could be alot of things, tell us more.
no curtains blocking airflow, no carpets either. I have closed dampers in two warm bedrooms and opened in both master bed and bath. do you think the system should be draained for air blockage? or is the run too long?
Has the system worked properly in the past or is this something new? You could need something as simple as bleeding air out of the system. How are your zones controled, zone valves or circulator pumps? If a pump goes out water will not move threw the pipes, but your first few raditors still get some heat because of gravity. But if you have just 1 pump and the other zone is working that would rule that out.
I would try bleeding air out first & check all raditors for air blockage. See if fintubes are clogged with dust dirt, ect.., thake the hoover to them if needed. I have some old CI raditors in our house, and if I have air in the system the top of the raditor dosen't get hot. There is a bleeder valve on each rad., I open till I get a stream of water with out air , then close it. I can instantly feel the heat move threw the rad.
Sometimes you will find a bleeder on the elbow fittings @ the end of the fintube, use that. Or you should have a air scoop on the whole system.
there is a circulator pump on the whole system, and zone valves for control. the system is on the second floor and the whole run is about 175-200 ft long. the system seemed to work ok the first couple of years. I did hear water moving through the system, does that mean the water in the system is low? can I bleed the system , or do I need a pro to do it. I'm going to put thermometers in the two warmer bedrooms and see what the temp difference is. there is no blockage from outside sources such as dusty, dirty fins or dog hairs etc.
There should be a purge valve for your system, which is basically a hose bibb on the boiler board. If it's set up as I would have it, you can open the makeup water valve, open the purge valve, and flush new water thru the system. Doing this *may* purge air from your system--connect a garden hose to the purge valve, and put the other end of the hose in a 5-gallon bucket so you can see if any bubbles of air come out. Purge for a while... 15-20 minutes, not just a few. If you don't get any bubbles then that wasn't the problem... if you get a lot then it probably was. If it's possible, isolate the downstairs and just purge the upstairs.
I am assuming you don't have antifreeze in your system, or anything other than water.
Take a photo of your boiler board if you can and post it.
This will work if simple bleeding will not. But caution needed if adding a great deal of cold water to a cast iron boiler while it hot. Thats if you have a CI boiler and where the hose bibb is located in the piping.
That's a good point. You'd certainly shut the system off and let it cool before purging.
daughters bedroom, the first in the rum is 80 degrees, the master last in the run is 67 degress, therm is set at 68. what the ^%*&^is going on
You should probably get a radiant contractor to check it out. Where are you located?
Hi, as you said, with a run of about 200' and only using 1 circ. with zone valves and the first year or so it worked fine. That summed it all up. There is your answer. The pump itself has gotten weaker from all that work. The brand will make a huge differance, also the size. If it is your standard taco green 007 throw it away. You could step up to a grundfos 15-42 or a 26-96 for more flow. with alot of feet of head and pipe and multiple zones your losing flow,your biggest killer. Getting the water back at a warm temp in a hurry will be your best bet.
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I am not a heating pro, but I have been around my system a number of years.
I have a hot water system with CI & fin tube radiation both.
If you are hearing noise in the pipes you are hearing the air move with the water.
Bleeding the air out of the system can be a easy thing, but then something air gets trapped in the system and you have to purge the system to force the air out.
Your system should have an air scoop to automatically remove air as the system is in operation, but that always doesn’t work. Your system is under a pressure so by manually opening the bleeder cap air should be released. Let air release until you get a solid shot of water. You should have an auto fill that will let water in, as the system needs it, so this will add water as you release water.
You might have to do this a number of times in a number of different locations, if you have bleeders elsewhere in the piping. Bleed, let the system run; bleed again, until all air is released. As the water circulates air will move to different places. If you pump placement and piping is correct, the air should be forced out, but a pocket of air can be challenging.
Photo#1 bleeder on CI rad
Photo#5 auto fill and air trap, red cap
photo#6 bleeder on heel of elbow fitting, often found in the piping.
Your pics show a radiator system, I have a hot water system. Do you know how to air bleed one?
That was a hot water rad.