Different temps in each bedroom

bentz69

Second floor of the house has 4 bedrooms that all see different temperatures. I will list the specs of the bedrooms below. 1st bedroom is currently empty but will likely be a babies room. 2nd and 3rd bedrooms have a 11 and 15 year old and the 4th bedroom is the master. A Nest thermostat for heat only is located in the master. We have a Burnham v84 oil boiler for baseboard heating and hot water that is set to 195°. There are 3 zones (basement, 1st floor, 2nd floor) each with a new Taco 007 pump and Taco 3 zone relay. Each floor has nest thermostat. Hardwood floors throughout the whole house and no carpet.

The kids have been saying that their rooms have been cold so I placed a temperature sensor in each of the 3 bedrooms. After checking each sensor and the master bedroom thermostat numerous times throughout the day for the past 2 weeks, I discovered that the 1st bedroom is always 4° colder then the master. The 2nd and 3rd bedrooms are always 3° colder then the master. This may not seem like a big difference BUT, we leave the thermostat set to 66-67° which is comfortable for all of us during the day and night. 63° to sleep is too cold for the kids.

I pulled the covers off every baseboard. I confirmed the fins are all oriented correctly, straightened any bent fins, vacuumed all the dust/debris, and sprayed the fins with vinegar/water mix to clean them. There are no obstructions or any items blocking the bottoms of the baseboards and all baseboards are fully open. I also confirmed that every baseboard is full of fins from end to end with no bare pipe.

We moved into this house about 3 years ago. Last spring I changed all 3 circulator pumps and installed the 3 zone relay to convert the line voltage system to 24v for the new Nest thermostats. At that time, the basement and 1st floor had old Taco 007 pumps and the 2nd floor (where the bedrooms are located) had a Armstong Astro 230ci 3 speed pump set to speed 2. Now every zone has new Taco 007.

I believe the loop runs like this. Master bedroom to 1st bedroom to 2nd bedroom to 3rd bedroom to hallway bathroom to master bathroom to master closet back to boiler. I took some temp readings with the infrared gun directly between the fins. I was reading roughly 155°-160° in the master bedroom and between 140°-150° in the other bedrooms.

I have read about covering a section of fins with aluminum foil which sounds like an easy fix for the master bedroom. But, if the baseboards are undersized for the other bedrooms then I would like to have that fixed. Especially the 1st bedroom if we plan to have another baby.

Is it possible that the Taco pump is not powerful enough for the 2nd floor? I could swap the Armstrong pump back in and turn the speed up if that would fix the problem.

Any ideas?

1st Bedroom - 111 ft2 / 892 ft3 - 4' of baseboard
2nd Bedroom - 148 ft2 / 1184 ft3 - 8' of baseboard
3rd Bedroom - 156 ft2 / 1251 ft3 - 8' of baseboard
(Master) 4th Bedroom - 275 ft2 / 2200 ft3 - 14' of baseboard

bburd

If you did not have this problem before you changed the pump, you have your answer; but you may not need to change it back.

It’s normal for the baseboard temperature to drop as the water flows through the rooms in a series baseboard loop, but the baseboards should have been sized to account for that. “Should“ is the key word.  A slower flow rate means a larger temperature drop through the circuit.

Square footage doesn’t replace a heat loss calculation, but it seems clear that the master bedroom radiation is out of balance with the other bedrooms.

I have used the aluminum foil trick with great success to solve this problem in more than one house. It costs virtually nothing, so you may as well start there. Try wrapping perhaps 25% of the finned baseboard elements in the master with foil all the way around, so air cannot flow through the fins, and see how you do. Adjust as needed.  You will almost certainly be able to bring the rooms into balance under usual conditions. Of course changes in sun and wind direction mean the rooms will not always be in balance.

You would need to consider adding finned element in the other bedrooms only if that zone will not maintain its setpoint on a very cold day after you’ve gotten it balanced with foil, and you have tried increasing the supply water temperature as far as it will safely go (this depends on the type of boiler you have). 

mattmia2

you can start by closing the damper on part or all of the warmer rooms to see if you can balance it that way before moving on to foil.

GroundUp

It sounds like the cold bedrooms in question have their own thermostat and zone circ, so essentially it's running nonstop and never catching up at night. Is that correct? I would think the 007 would be sufficient but we will need to know the system pressure and the total length of that loop along with height of 2nd floor BB relative to the pressure gauge in order to accurately determine what's going on. Can you get temp readings at the supply and return (in the boiler room) for that 2nd level zone? Is it possible that it's piped in a fashion that the return water from the basement or 1st floor is being sucked into the supply of the 2nd floor zone making the SWT lower than the others?

bentz69

bburd said:

If you did not have this problem before you changed the pump, you have your answer; but you may not need to change it back.

It’s normal for the baseboard temperature to drop as the water flows through the rooms in a series baseboard loop, but the baseboards should have been sized to account for that. “Should“ is the key word.  A slower flow rate means a larger temperature drop through the circuit.

Square footage doesn’t replace a heat loss calculation, but it seems clear that the master bedroom radiation is out of balance with the other bedrooms.

I have used the aluminum foil trick with great success to solve this problem in more than one house. It costs virtually nothing, so you may as well start there. Try wrapping perhaps 25% of the finned baseboard elements in the master with foil all the way around, so air cannot flow through the fins, and see how you do. Adjust as needed.  You will almost certainly be able to bring the rooms into balance under usual conditions. Of course changes in sun and wind direction mean the rooms will not always be in balance.

You would need to consider adding finned element in the other bedrooms only if that zone will not maintain its setpoint on a very cold day after you’ve gotten it balanced with foil, and you have tried increasing the supply water temperature as far as it will safely go (this depends on the type of boiler you have). 

I will try the foil trick today and continue to monitor the temps.

GroundUp said:

It sounds like the cold bedrooms in question have their own thermostat and zone circ, so essentially it's running nonstop and never catching up at night. Is that correct?

Not exactly sure what you mean? The entire second floor with all bedrooms is one zone. The thermostat is the master bedroom and controls the whole zone. The temp sensors are there just to give me readings. I am not using the temp sensors to control the thermostat. But to add one thing, YES, each bedroom is seeing a different temperture and they are never even with each other.

GroundUp said:

I would think the 007 would be sufficient but we will need to know the system pressure and the total length of that loop along with height of 2nd floor BB relative to the pressure gauge in order to accurately determine what's going on. Can you get temp readings at the supply and return (in the boiler room) for that 2nd level zone? Is it possible that it's piped in a fashion that the return water from the basement or 1st floor is being sucked into the supply of the 2nd floor zone making the SWT lower than the others?

These are the measurements from today......
15' of pipe from the boiler to the second floor baseboard.
I am guessing to measure the loop you need to simply add the length of pipe around the whole zone? If so, I measured 150' of pipe on the second floor (this includes bends into the baseboard and back under the floor). The 150' does not include the 15' from the boiler to the second floor and the 15' back to the pump. Total comes to 180' of pipe. Is that the correct way to measure the loop?

Supply temps are 160-170 when measured at the beginning of the supply pipe.
Return temps are 130-140 when measured right before the pump

The return water from the other zones is not being pulled into the second floor zone. Its not piped in a way to make that possible

Included a pic of the boiler gauge for pressure

Jamie Hall

I suspect very much that it is plain and simply that the radiation in the various rooms is poorly matched to the heat loss. The difference with the previous pump may have been that it had higher flow, and therefore lower delta T, making the radiation in the cold rooms warmer and masking the underlying problem.

If that is so, the aluminium foil trick in the master bedroom should help, as it will effectively better balance the radiation.

motoguy128

I wonder if lowering the water temp would help. So long as the boiler doesn’t short cycle, you don't want water any hotter than needed to maintain temp on a deign day.

You should time the length of cycles and compare it to outside temperature vs design conditions. So if its 30F average over the previous 8 hours you are probably about 50% of design. Then compare.

Lower water temp will increase run times and should help balance temperatures a little.

Jamie Hall

I would doubt very much that lowering the feed temperature would help at all, unless it were accompanied by a correspondingly higher flow rate to reduce the delta T. If that isn't done, the downstream radiation will be getting even colder water than before...

You either have to get the delta T much lower (higher flow) or reduce the output of the upstream radiation.

bentz69

Ever since we moved in there have been small issues with the heating system. It took me a little while to figure out that the check valve for the 2nd floor was stuck open which was constantly causing thermosiphoning. The second floor would get very hot (low 80s) when the zone was off but the 1st floor was running. I dealt with that issue for a while until I opened the system last spring to install new pumps, 3 zone relay and the nest thermostats. I really cant say if the swapping the pump caused the problem because there have been different problems since moving in. I can say that before I changed all 3 pumps to taco 007s, the old pumps for the basement and 1st floor were also taco 007's but the 2nd floor had the armstrong pump. I don't know if the previous owner changed the 2nd floor pump to the a variable speed armstrong pump because it was necessary to have a higher flow. The armstrong pump was on speed #2. The previous owner also had the boiler set to 180.

I covered about 3.5' of fins with foil which is roughly 25% of the total fin area. I had heat off all day to clean all the baseboards and all the bedrooms dropped to 61°. When I turned the heat back on, the master bedroom quickly rose to 66 while the other 3 rooms were creeping up to 63. I closed one of two baseboards in the master (7' of the total 14') and the rising temp slowed while the other rooms caught up. As the master touched 68, all other rooms were still around 65-66. I had to partially close the second baseboard to allow the other bedrooms to catch up. Eventually 3 of the 4 rooms were the same temp while the smallest bedroom was 1° cooler.

What does this tell you?

bburd

That you are on the right track to getting the zone balanced, but there is something else going on besides poorly sized radiation. 

A Taco 007 can heat an entire medium sized house with a 20° delta T or less. You have 3/4” pipe and 34 ft of finned element in that zone, nowhere near the limit for standard 3/4” baseboard (about 65 ft at a flow rate of 4 gpm and 20° delta T), yet you have a 30° delta T. Even if it’s high output baseboard (unlikely), that is excessive.

Something is restricting the flow rate. If there are shutoff or balancing valves, make sure they are fully open. It’s possible there is some weird restriction like a detached valve disc, or debris lodged somewhere in the circuit. 

Robert_25

I would take a closer look at that check valve. It might be dirty/sticking and causing a flow restriction. There is no way you should see a 30F drop through a 3/4" baseboard loop with only 34' of element.

bentz69

@bburd and @Robert_25 all valves are fully open. I wouldn't even know where to look for any type of restriction other then the pump/check valve. All the check valves were also replaced when I put the new pumps in.

I was looking at flow charts for the 007 vs the Armstrong pump that was previously installed. Is the chart stating that a 007 has a maximum head of 10' and the armstrong has a maximum head of 17" when on speed #2 (which is the speed the pump was set to)? The second floor baseboards are about 15' from the boiler in the basement.

If Robert said there is no way I should be seeing a 30° drop through the loop, is the taco 007 undersized to push that water fast enough which is causing the large temperature drop? Or perhaps the Armstrong pump was used to mask another problem?

Jellis

Hey @bentz69,
I think you are on the right track with blocking off the baseboard... with your current setup I would expect the first room in the heating loop to be the warmest since that is the room that gets the warmest water...

4 rooms with one T-stat to be within 3-4 degrees is demanding a lot of the system in my opinion... Each room has slight differences that will make it cool down at a different rate than the others. I'm sure you can tweak it to your satisfaction.
It does not sound to me like anything is "wrong" with the system.

for more exact control of the temp in each room I would suggest separate thermostats for each room.

Jamie Hall

Is that 15 feet up, or is that the physical distance. What matters, though, is the total length -- and resistance -- of the pipe. The Taco actually has more flow at intermediate head loss than the Armstrong (shutoff head, which you quote, is irrelevant).

So... forgive me if you have already answered this, but what is the total length of the pipe plus including the radiation, from where it leaves the pump to where it comes back to the rest of the basement piping, and what size is the pipe?

bentz69

@Jamie Hall plumbing is not my expertise so ill explain what I see.

-For the 2nd floor zone
-Pipe from the top of boiler to first bend is 5'
-90 bend and travels horizontal for 6'
-90 bend and travels vertical for 10' to the 2nd floor baseboard
-is that considered 15' of head?

The total loop from the boiler, including bends, through the baseboards and back to the pump is 180'. 3/4 pipe

hot_rod

Both those checks are misapplied.
Really do not want a check on the suction side of the circulator, the red one. The flow restriction on the suction side can cause cavitation
The new check on the Taco looks like a well pump, flat disc check? Probably oversized and that could prevent the Taco from fully opening the check.
Checks should really be sized by Cv or flow rate, not pipe size. Also, hydronic checks are best suited for systems like yours.

Jamie Hall

You are by no means the only one to confuse static and dynamic head. Static head -- which we don't care about -- is the height to the highest point. That's your 15 feet. Dynamic head is the head lost to friction of the flowing water in the pipe. In your case, the head lost in 180 feet of 3/4 inch pipe (plus the fittings...).

A very rough squint at the head loss and pump curve for the Taco 007 suggests that the flow in that loop should be somewhere around 5 to 7 gallons per minute (it would have been similar with the Armstrong).

As @bburd wrote, something is amiss here. Where it is I wouldn't care to say --but something is obstructing the flow.

mattmia2

Couldn't they just replace the flow check with an iron or brass coupler and get the 00 series ifc for the 007 pumps?

bentz69

hot_rod said:

Both those checks are misapplied.
Really do not want a check on the suction side of the circulator, the red one. The flow restriction on the suction side can cause cavitation
The new check on the Taco looks like a well pump, flat disc check? Probably oversized and that could prevent the Taco from fully opening the check.
Checks should really be sized by Cv or flow rate, not pipe size. Also, hydronic checks are best suited for systems like yours.

Here is a link to the checkvalve. Not knowing much about checkvalves, I used what was recommened to me and obviously followed the same orientation of the original check valve that has likely been there since the house was built in 1987

Just to clarify, the red pump is the old armstrong pump with the old check valve that was clogged. The taco pump with the brass checkvalve is the replacement. But the flow is still the same

https://www.supplyhouse.com/Bluefin-SLCT075-3-4-Threaded-Spring-Loaded-Check-Valve-Lead-Free

Jamie Hall said:

You are by no means the only one to confuse static and dynamic head. Static head -- which we don't care about -- is the height to the highest point. That's your 15 feet. Dynamic head is the head lost to friction of the flowing water in the pipe. In your case, the head lost in 180 feet of 3/4 inch pipe (plus the fittings...).

A very rough squint at the head loss and pump curve for the Taco 007 suggests that the flow in that loop should be somewhere around 5 to 7 gallons per minute (it would have been similar with the Armstrong).

As @bburd wrote, something is amiss here. Where it is I wouldn't care to say --but something is obstructing the flow.

Please tell. Did I screw something up when I installed these pumps and checkvalves?

mattmia2 said:

Couldn't they just replace the flow check with an iron or brass coupler and get the 00 series ifc for the 007 pumps?

If the checkvalve I am using is the problem then your idea sounds pretty simple to fix. When putting the parts together to swap the pumps and checkvalves, I tried to keep everything the same. Thats why I didnt use a pump with a IFC

clammy

Usually circulatory are installed on the supply side pumping away from the expansion tank . As hot rod has stated wrong location for those check valves also ,usually when pumps are oriented as your are on the return flow checks are installed on the supply to each zone . The better approach for your system would have been some taco zone valves mounted on the return and a nice ecm pump pumping away from your expansion tank and air eliminator . Possibly you can have some reverse the piping for your second floor w the now coldest room being feed first would help but Doing a room by room heat lose will tell the truth as to why .peace and good luck clammy .

bentz69

Ive noticed over the past 2 days that the temp in each bedroom is much closer to the master since I closed the baseboards in the master. I have also noticed that all 3 bedrooms drop temperature much quicker then the master. If I set the thermostat to 67, I can achieve 66-67 in each bedroom before the thermostat shuts off the heat. However, each bedroom besides that master will drop temps much quicker.

For example, thermostat is set to 67 while we sleep and each room is roughly 66-67 throughout the nite which is good. During the day I will turn the temp down to 63 because nobody is in the bedrooms. The master will stay between 64-65 but all the other bedrooms will drop to 60-61. I turn the heat back on in the evening and each room is heating up quicker then the master because the baseboards are closed in the master.

mattmia2

How many outside walls and windows does each room have? Outside walls are where the heat loss is (and the ceiling but that presumably is more or less proportional). Windows have a lot more loss than solid wall.

bentz69

mattmia2 said:

How many outside walls and windows does each room have? Outside walls are where the heat loss is (and the ceiling but that presumably is more or less proportional). Windows have a lot more loss than solid wall.

The smallest bedroom is the 1st bedroom as referenced in the original post. It has 1 outside wall, 1 window and 1 skylight. Baseboard is under the window. It is unfurnished.

Bedroom 2 has 2 outside walls, 1 large window and the baseboard on the outside wall without the window

Bedroom 3 has 2 outside walls, 1 large window and the baseboard is under the window.

Master has 2 outside walls, 4 windows, 2 sections of baseboard which are both under the windows.

mattmia2

Are you sure the master isn't getting a heat call occasionally that is keeping it at 64-65 and the other rooms are just cooler because of the balance issue? It seems the master should have the most heat loss if the construction is all similar, but it also probably has a little more radiation in relation to its loss than the other rooms.