How good are your windows there? Are they double- or triple paned?

Are all the windows closed?

windows closed, double pane windows.

I am at a loss any other ideas?

Turn on the heating system on high so it doesn't shut off. Wait for 30 min to an hour. Go into that room and see if you feel heat coming from heat source. (whatever it is.)

The problem could be that the temperature around your control satisfies the thermostat and shuts the system off. The room you are referencing, the thermostat because it's not located there is shutting the system off.

If you don't feel heat coming from heat source in room, use those clues.

If you do feel heat, it could be what I mention above. (design problems - the invisible problems of a system that don't become apparent until you live there.)

PS: I'm only guessing, I am not there. So keep this in mind.

You posted in this forum about this problem and since then you had insulation upgraded in only that room or in the entire house?

the heat is coming from baseboard as normal. I changed the thermostat to the nest had it running at 68 for multiple hours and that room still colder by 5 degrees. These rooms got dense packed insulation and this room still cooler after.

We had the same problem at the end of the run. Install a HVAC booster

BA M,tell us more about a HVAC booster. What is it,where does it hook up,how and what does it boost? Please don't tease us without giving some background on it.

There are two approaches to this. One way is to cut heat loss from that room specifically. This may or may not be practical. If your air leakage rate is already very low, it will be difficult to improve. If your insulation is already exceptional, adding more won't gain you much.

The other solution is to add heat. You can add more of the same type of radiator or different radiators or fan coil air handler or in floor radiant heat. Although it might work, reversing flow moving the room heat to a point in its zone that is closest to the boiler outlet might cause other problems in heat balance. You could also just move that loop for that room closer to the boiler outlet. The effectiveness of changing the flow is dependent how your system is set up. There must be a significant temperature drop between supply and return at the boiler. Keep in mind too, that return water temperature needs to be low if you are to take advantage of an high efficiency boiler.

BTW, what is "dense packed insulation"? Normally, you don't want insulation packed because it cuts down on the air pockets that are slowing heat transfer.

Actually you do want dense packed insulation. It retards air flow, and, to a point, increases r-value per inch. The air flow thing is key though, many older houses have very poor air sealing details, and blowing in dense packed cellulose is quite effective at reducing the leakage rate.

When Austin said to turn up the heat, I think he meant to high - 80 or 90, to see the effect of the heating system. Also, you said your corner room is 5° colder. Than what? The rest of the house? The thermostat setpoint? Also, what is the outside temperature. As it gets colder outside (i.e. well below freezing), one would expect the difference to be greater, especially if it's poor insulation (which you say you don't have) or leakage.

I changed the thermostat to the nest had it running at 68 for multiple hours and that room still colder by 5 degrees.

This points to system design problem. You can change the thermostat all you want. You can move the thermostat to this room, then the temperature will be 5 degrees warmer in the rest of the house.

Your biggest weakness is the control to the system. The thermostat can not tell the temperature of a space much farther than maybe 10 feet. Insulation while important will not solve this issue under extreme out door ambient conditions otherwise known as load of the structure.

If the thermostat was in this room you would likely be complaining the other rooms are too hot. System Design is currently a bad word in this business... in climates of temperature extremes you can't get around it.

To fix this you should look to zoning control options to your boiler set up. This isn't something you should try to do yourself. Zoning of HVAC equipment is a specialty trade. If you go this route you want to make sure whomever you select has experience in this realm.

OR

You could add an additional small heating appliance to this room with an independent control that is located in this room. (This would be less elegant solution, but also cheaper.)

If the room has not extraordinary problems with heat loss and the heating system is working properly, addition of a length of baseboard is the likely solution and should not be that expensive. Adding insulation or air improving air sealing might be more costly initially, but might be lower cost over the long run. What is chosen depends on solutions and costs to be calculated.

Discussion of zoning is premature at best and inappriate at worst. We don’t know what kind of boiler it is. 1) Running a small zone on a low mass boiler can be troublesome. 2) The additional piping, and valves and circulator for an additional zone that is not needed for comfort will be a lot of additional cost. That may especially true since the basement space is finished and may see considerable distruption.

"When Austin said to turn up the heat, I think he meant to high - 80 or 90, to see the effect of the heating system. "

Yes, Austin's is the best suggestion for right now. Do be sure that the emitters (baseboard) in that room are up to the same approximate temperature as the other ones in the home. Crank the t-stat up to max and make sure that the circulators are running for a half hour and measure the temps. If you have a point and shoot IR thermometer, use that. They are so inexpensive these days and so useful. Just check the temp of the baseboard heat in that room, check in a couple of other rooms and then recheck the cool room. Record the numbers. Are they the same? It the cold room has significantly cooler baseboard, the first task is to figure to why. We need to know if the system is working as it should before going any further.

For all we know, it is not a straight loop as we might expect. This could be a case where monoflow Ts are used and someone has shut off a valve for that room. OP, have you looked over the whole system as best you can where pipes are visible? Have you figured out how the water flow works from the boiler to back into the boiler? You have one thermostat, one circulator pump? What kind of boiler do you have? What water temperature are you running? (There is probably a thermometer on your boiler.)

Here is my boiler name etc. When I meant temperature difference I meant the 3 adjacent rooms which are on a zone together the corner room temperature in the room is 5 degrees cooler compared to thermostat. However as someone mentioned when this zone turns on at night to 68 this room temp is 66 but overnight I notice it to be cooler.

"jjvantol

Actually you do want dense packed insulation. It retards air flow, and, to a point, increases r-value per inch. The air flow thing is key though, many older houses have very poor air sealing details, and blowing in dense packed cellulose is quite effective at reducing the leakage rate."

Just in case anyone goes away with the wrong impression, insulation should NEVER be compressed. If you have an air leakage problem then solve this, but not by compressing insulation.

shivece, that is the heat loss side of the equation. the other side is heat delivery, you fix on the first side with better windows, insulation and air sealing. The other side is more heat delivery -- longer baseboard rads most likely. Either way, the original heat design was not quite correct or mods to the house messed it up.

xxnonamexx, I can't tell much about the boiler from the pic. It looks most probably an old school, oil-fired boiler meaning 80% efficiency or less.

Are these temperature differences measured with the same thermometer or with corrected thermometers? Inexpensive thermometers can be easily a couple of degrees different.

You need to find a boiler specialist that specializes in boiler zone systems.

With the additional information you provided this is probably your best bet.

I used the laser thermometers. You think the zoning is incorrect?

Don’t get me wrong, I believe that room feels colder to you and it needs help. If by laser thermometer, you mean an IR thermometer with a laser indicator, try something else or be sure that you are using it well. They are quite dependent on the type of surface that you point them at. If you are measuring on an identical surface in each room, your are OK. It can be as simple as a small stack of the same size envelopes, or identical pillows with identical pillow cases,use your imagination. Otherwise, a couple of quickly equilibrating spirit thermometers that have been compared to each other and a correction factor applied are better. The most simple way is to just use one thermometer, but that is time consuming and the temperatures might change during the process.

I don’t think that anyone can say that the zoning is “incorrect”or not. We don’t have enough information. If there is a large temperature differential between two rooms on the same zone, the ratio between heat loss and heat provided is different with those rooms. Assuming that there is nothing wrong with the heating system, you need to cut the heat loss or add some heat in the problem area. Adding a little baseboard or higher output baseboard should not be terribly complicated or expensive.

You need a hydronics person to check out your system and make sure it is working correctly. If it is, and you decide to add heat, that person likely, or his company, can propose that addition and give you a cost.

If that is an oil-fired boiler, you need to have it cleaned, inspected and possibly adjusted, annually. If you don’t, you risk running inefficiently and a high probability of unexpected mechanical failure. The people that do that work are, likely, the same ones that install additional heat and may deliver your fuel oil. Lots of companies do all three. Perhaps that sticker on your boiler names an outfit that knows your boiler well. I Is natural gas available in your location?

OP,

Laser thermometers while very easy to use, can be misinterpreted if you're not using them properly. Buy several digital thermostats or digital thermometers and place them in each room of the zone in question on a 'interior wall' in each room and compare the values from there.

If there is a problem with the boiler zone a company that specializes in that specialty is your best shot at correcting a problem 'if' one exists. Otherwise, you'll probably only make it worse or continue to chase your tail.