New boiler, Insufficent heat

Melhe

I have a large house built in 1995 with radiant heat system. Because the master bedroom getting cold we called a contractor and changed new boiler Weil -Mclain Ultra series 3 with new uponor system. Based on their calculation, master bedroom need 13100 total room load. great room need 30660 total room load. output temperature set 120. return around 100. Unfortunately, Master bedroom is still very cold. When the outside temperature dropped to 20s, the bedroom temperature dropped to 50s. I have to live in the guest bedroom this winter. The contractor came back changed master bedroom pump to TACO variable speed delta T and purged water inside tubing. But it didn't help. When I feel the MB tubing temperature output and return, they r nice and warm like other rooms. but the floors on master bedroom seems not warm... The contactor told me I should demolish the basement ceiling and install proper insulation under master bedroom which was not done initially. because of the heat loss, the temperature doesn't go up. It seems not making sense to me because other part of the house was in normal temperature esp great room much larger. they were all not proper insulated at the time of building of the house. The only problem is the master bed room. The ceiling of basement which is right under the MB is normal temperature and the basement temperature is the same as thermostat settings.... That part of basement was finished , decorated.... Before I spend another 8k to demolish the basement ceiling to install insulations. ( I am sure there are additional costs to refinish basement ).  I'd like to ask experts here what else could be the problems that mb doesn't generate enough heat. 

Please help, many thanks

Melhe

Some details

I d like to post a few pictures to help understand the situation . The first picture showed zones in mb , master bath and dressing room

Melhe

Additional info

Current outside temperature is 18F

Current MB temp 56.  ( setting 71 )

There are two zones inside master bedroom. Both in 120, out 95- 103

Floor temp inside MB  62-67

Floor temp other rooms. 77-81

Tom_133

Hmmmm...

What size is the master bedroom, I know you stated how many btu's but how big is it? If possible how many loops feed it?

Melhe

Size

It is 725 sf With lots of windows . i installed cellular shades recently . not helping much . I don't know how many loops . I only know there r two zones for that room. Forget to say . Master bathroom and dressing room r cold as well. All the rooms belong to that zone group in picture 1 r cold ....

Pughie1

Floor covering

What type of floor covering for the MB Zone?

Paul Pollets

Application + Insulation

You don't mention how the MB is heated. Embedded or Staple-up? Climate Panels or Quick Trak? If the contractor used a software program to design the system, (ie Uponor ADS) there are "what-if" queries that can show water temp requirements depending upon floor covering and insulation values. 120 won't do much if there is no underfloor insulation or a staple-up application without transfer plates or insulation. Do it right or do it over!

Melhe

floor cover

Hardwood floor throughout the house

Melhe

MB heating design

I am not sure how detail designed under the MB, But I know the loops r embedded inside concrete slab. But the original designer didn't put insulation under it. My question is why other part of house without insulations doesn't have problem with temprature, But MB zones r the only zones have problem. I even couldn't keep the temperature inside small walkin closet which has no windowns and door is closed all the time.

I am wondering if there r possible any blockage through the piping because there r small rust and water leakage though the piping under MB in the past before the construction.

Have you guys heard of infrared thermographic scanning to detect if any blockage or leaking? would it help if I hire some thermogapher to check it out?

Gordy

Slab?

Is this gypcrete over pour.



The btus are going somewhere, and not up. You stated you have a lot of glass area in master bedroom.



Is the master bed room on the north side of the house?

Does it not get solar gain like rooms that do heat well?



1. If you want to use that low of water temp you need insulation under the floor.

2. Could be a flow rate issue.

3. Could be circulator sizing issue.

4. Could be restricted loops, but you have flow gauges on the manifolds right.

SWEI

Did anyone mention

that there appears to be no outdoor sensor installed?

Melhe

floor temp

Yes, there are lots of windows. No matter what. I think it shouldn't feel freezing cold in the room 53 degrees. When I step on the floor in the MB, The floor feels really cold as well.  As soon as I step out of those zones. Floor feels warm again.

I don't know the detail design original built because I wasn't not the original owner of the house. I forwarded questions to the contractor . hopefully ill get answer soon

Melhe

outdoor sensor

I don't think so, would that be any problems?

Melhe

outdoor sensor

the contractor said he'll install after system stabilize . it shouldn't affect anything now

Jean-David Beyer

If you do not connect the outdoor sensor to a W-M Ultra 3

It will run at the maximum temperature end of the boiler reset curve for whatever thermostat input is in effect (the highest priority one; i.e., the one with the lowest number that is calling for heat). The highest is usually #1 that is by default, an indirect hot water heater.

The next highest is usually #2. And what circulators are running depends on how the control is programmed. Normally, input #1 runs only the circulator to the indirect. Normally, input #2 runs both the boiler circulator and one of the system circulators. If it is set up wrong, it might run only the boiler circulator, or it might run only one of the system circulators. Both would explain cold results.

Harvey Ramer

It looks

to me like you only have flow going through one loop on that manifold. Based on what the flow meters are looking like. Make sure the thermal actuators are snapped on tight. I have seen many of them partially popped off. That prevents the valve from opening. Also check to make sure they are wired properly and receiving power. Could be a blown fuse in the zone control module.



You are correct. The floor temps should be higher with the architecture as it currently stands.



Harvey

Melhe

Outdoor sensor

I don't understand your post in detail. Do you mean without outdoor sensor the boiler will not prioritize the call from room temperature , instead it will prioritize the hot water calls?  yes, he limited hot water heating to 6-7 min each time. But I will relay your post to him to get outdoor sensor installed.

I thought the purpose of outdoor sensor is really to get the heating system shut down when outdoor temperature gets too high.

Melhe

Pictures

I tried to check . It seems all blue caps r tight on . The wire panels all lights r on . I don't understand in detail . Just took a couple of pics . First one is the electric panel . Another is the flow meters of the both master bedroom zone tubing . It seems have flows . I don't know where else I can check to find out where has loopings without flow

Jean-David Beyer

I don't understand your post in detail.

I am sorry I was unclear.



"Do you mean without outdoor sensor the boiler will not prioritize the

call from room temperature , instead it will prioritize the hot water

calls?  "



No, I did not mean that. I meant that the boiler will continue to use the priorities, with priority #1 to be the most likely to run, then priority #2, then priority #3. And by default (and I see little reason to change it) priority #1 is for the Indirect, priority #2 is normally used for the first heating zone, and priority #3 can be used for another heating zone.

Each has its own reset curve (although the indirect does not actually reset).



What I meant was that if you do not connect the outdoor sensor, the boiler assumes it is maximum cold outdoors and puts out the hottest temperature that the reset curve associated with that particular priority provides, irrespective of what the outdoor temperature might be.



"yes, he limited hot water heating to 6-7 min each time."



For my boiler, which is oversize (it is the smallest Ultra 3 there is), so I have no trouble getting enough heat. I live alone, so my hot water needs are modest. I allow the top priority indirect hot water heater to run up to the default of 30 minutes because I have never seen it run over 15 minutes anyway, and it runs only twice or perhaps three times a day, so it does not matter to me if it steals this from heating the house. I figure I might as well let it restore the maximum.



"But I will relay your post to him to get outdoor sensor installed."



Go ahead if you like. What would worry me is that if he needs the contents of my post, it almost certainly indicates that he did not read and understand the installation manual. The contractor who installed my Ultra 3 had the same problem. It seems a matter of honor to not read the installation manuals. Maybe that works for coal fired convection hot air furnaces, but is sure does not work for mod-con boilers. It was a real surprise to find out that I knew more than the installing contractor did about the boiler they sold me.



"I thought the purpose of outdoor sensor is really to get the heating system shut down when outdoor temperature gets too high."



Not really. It does do that; that feature is called Warm Weather Shutdown, that will turn home heating off, but leave the boiler alert when the indirect needs heat. The default warm weather shutdown temperature for the Ultra 3 is 70F outside temperature.



But the main purpose for outdoor reset is so that the boiler will put out the minimum possible heat consistent with keeping your house warm enough. With the outdoor sensor connected, and the reset curve properly adjusted you almost do not need an indoor thermostat at all. As it gets colder out, it increases the supply temperature of the water to the radiant floors (if you have them) or your baseboards, panel radiators, etc. As it warms up outside, it reduces the supply temperature and the house keeps the temperature you want.



If you have a high mass system (one of my zones is slab at grade radiant), this keeps the temperature very even with no overshoot or undershoot.



But the main advantage is that the lower the supply temperature, the more efficient the heating of the water is because the difference between the fire temperature and the water temperature is greater, and so the heat flows into the water that much more efficiently. A secondary advantage is that the lower the supply temperature, the lower the return temperature will be, and if it is low enough, the exhaust will condense and give you up to about 10% more efficiency than if no condensing were occurring.

Melhe

Thanks for the explaination

I really appreciate the detail explaination.  I checked my boiler setting. Priority one was not set up if any different it makes.

Melhe

priority setting

Sorry my mistake. Just checked,  He set priority 1 as domastic hotwater

priority 2 is the radiant heat for rest of the house. Priority 3 was not set up

Melhe

Please advise

1. If you want to use that low of water temp you need insulation under the floor.

I don't want to use low water temp. He put boiler output as 150, but return water only 100, so when they mix up, the system output only 120. There is no manual adjustment to decrease return water volume into mixers.  Can I put boiler output 170s and try and see? He told me the tubings we use originaly has certain type of coating. The max temps should flow through the tubing should be no higher than 140.

2. Could be a flow rate issue. on the flowmeter it said 0.8. its automatic setting. not sure how to adjust

3. Could be circulator sizing issue : It was changed to TACO variable speed delta T( 00-VDT), Is it large enough?

4. Could be restricted loops, but you have flow gauges on the manifolds right. How can I find out?

Harvey Ramer

So you are saying

that all the zones/rooms connected to that particular manifold are not heating properly and the floors are staying cold?



Harvey

Melhe

That is correct

There r total 32 zones in the house . All those 6 zones in that manifold are cold . Other zones r able to maintain the temperatures

Harvey Ramer

So you actually

have six individual zones coming off of that six loop manifold? In other words. Each loop goes to an individual room?

Melhe

Master bathroom

Master bathroom zone belong to that manifold is somewhat warmer . I can feel the floors warm . Maybe it's marble floor with better conduction ? But not enough to raise room temperature to the settings . Both master bath and closet temp is about 61, 62 . But master bedroom . I don't feel any warmness on the floor . Room temp stays bw 54 to 56



But if outside temp raises to 50s . The master bedroom temp can reach the set temp 70s

Melhe

Yes , that's correct

Only master bedroom, kitchen , living room Dinning room supplied by 2 zones ( loops) . Rest rooms garages , hallways , bathrooms r supplied one zone per location . This time changed new boiler , I didn't connect the snow melting loops to the boiler . Because we never used it. Before , if I need connect that as we'll , one boiler is not large enough

Harvey Ramer

I should clarify some

terminology here. A zone will have a thermostat. A manifold will have multiple zones/thermostats. The loops coming off the manifold will be dedicated to a certain zone/thermostat. Some zone have multiple loops some only have one.



How many zones are on this manifold? How many loops are going to the MB? Hopefully they are labeled?

Harvey Ramer

Also

what part of the country are you located?

Melhe

Clarified

Sorry , I just clarified with my hb . There is one manifold with 6 zones / loops . There are two loops going in master bedroom controlled by one thermostats . Other 4 goes to master bathroom , master bath tub, dresser room/ hall way , sitting room , Master bath and master bath tub sharing same thermostat as we'll

Melhe

Zone 6b

Northeast . Zone 6b . It is exceptional cold this year

Melhe

My mistake again

There r actually 4 zones in that manifold . Because there r only 4 thermostat there . But 6 loops

Harvey Ramer

I live in

the northeast as well, but I'm not sure what zone 6b is. And you are right, it has been a little nippy this year!



Now you have 2 loops going into the MB. Each loop has .8 GPM @ a 20 degree difference between supply and return. That means you are putting 16000 BTU's into the space.



Floor should be warm but it isn't.



You have 3/4" hardwood floor above the heated slab and 3/4" wooden subfloor beneath the heated slab. The heat from the slab will travel close to the same speed down through the subfloor into the joist cavity as it will up through the hardwood into the room. So we know that your joist cavity is uninsulated. So I wonder if the ban board is insulated and sealed. The ban board runs along the outside perimeter of the floor joist framework. It is 1-1/2" thick. So in effect, if that space is uninsulated, and not sealed, you only have a very thin leaky wall right there. Even if that section is only 1' tall, you could still get enough air infiltrating the space to suck away all the heat from the floor.



Maybe you should insulate?



I most certainly wouldn't rip down the whole ceiling though. I would just cut out a narrow strip and have the joist cavities blown full. Then replace the strip, finish it and repaint so it blends in.



Shouldn't be that hard or costly :-)





Harvey

Melhe

Where r u located at

I am in New Jersey . Thank u so much for the advise . I was told the whole ceiling need to be demolished and refinished after the insulation . I appreciate ur advice . If u close by . Please contact me and give me a quote if u can help

Harvey Ramer

I am

in South Central PA about 30 miles west of Harrisburg. It would be a couple hr. drive to Jersey.



I don't do either drywall or insulation. I can but I choose not to, ever! Insulation is itchy and drywall is dusty.



If you need consultation I can do that. Just click on my user name and then click the contact button.



Harvey

Zman

Loops

Are you able to determine which loops service the under heated area?

Can you confirm the flow rate and supply/ return delta t on those loops specifically?

Once you are positive the btu's are being delivered, it then makes sense to talk insulation.

If your issue is inadequate flow, all the insulation in the world will not fix it.

Carl

Hydro

Radiant

I agree with Zman,

In the picture it looks like the loops are not balanced properly, (if every zone on that manifold is calling), turn up all thermostats serving that manifold, and when the red and yellow lights are lit up on the zone control module serving that manifold, check to make sure that the flow is the same for all of those loops. Adjust the knobs on the corresponding loops to ensure that all loops have the same reading, otherwise the water will follow the path of least resistance, and might not flow at all through other loops.

Melhe

insulation

Thank you for the advice. I asked contractor insulated the floor under the master bath today which is right above the pool room. Pool room has drop ceiling , so its easy to install insulation. Its not cold outside today. But I'll give it 24 hours to see if it make any difference...

Melhe

Flow rate

It seems all 4 zones ( 6 loops ) in that manifold couldn't generate enough heat. We insulated master bath today because that room is easier to insulate without damage basement ceiling.  i'll see how it goes. most loops indicated 0.8 and only one loop flow at 1.  both loops supply the bedroom flow at 0.8. should I adjust all the them to 1?

R there any other ways to tell the flow rate ?

Melhe

supply/ return data

All loops in that manifold doesn't work well ( under heated ). the worst two loops r under master bedroom.

How can I find out detail supply/ return data except flow meter? I can take additional pictures if needed. Please advise.

There r 32 zones in the house. only this 4 zones not working well.

Gordy

deleted