HVAC Guys please!!

[JZ67]

Woke up around 4 am cuz my bladder must be shrinking with age. I'm sure no one here can relate.

I notice that there is no air coming out of my vents but hear the unit running. House feels cool but I have a ceiling fan moving air. I go check out the thermostat and it is flashing 'replace battery' but reading at 24.5 degrees. The thermostat is set for 23.5. I replace the battery and the thermostat read 26.

I go to the furnace and pull the filter that I meant to change about a month ago and it is solid black. It was last replaced around April as I was finishing my basement and changing it every month. But, yeah solid black. I had to peal it back t make sure it started off white - it was so uniformly black. I replaced the filter.

Kids have been burning candles a lot lately...they think their dad doesn't know what weed smells like I guess. Smells a bit worse being masked by a scented candle. I hate those fucking obnoxious candles!

I open a panel and see the coil is frozen so I shut off the AC and turned the fan on. At 7 am, the coil is thawed out so I switched on the AC and it's blowing cold as normal. I should mention everything seemed to be running normally up until last night.

What should I be looking for now?

[ZR]

Rookie HVAC wanna be opinion.

If air was restricted enough because of the filter, yes it could freeze. Once A coil was clear of ice, did you confirm tray is draining properly? Also good idea to make sure inside of the A coil itself is not plugged / restricted.
Another often overlooked bit of maint, do you check airflow through the coils on outside unit at least once a year? Very easy for them to get plugged / restricted from dirt n debris.

[JZ67]

Rookie HVAC wanna be opinion.

If air was restricted enough because of the filter, yes it could freeze. Once A coil was clear of ice, did you confirm tray is draining properly? Also good idea to make sure inside of the A coil itself is not plugged / restricted.
Another often overlooked bit of maint, do you check airflow through the coils on outside unit at least once a year? Very easy for them to get plugged / restricted from dirt n debris.

I can't access the coil inside the unit to see if it is restricted or not. I clear off the outside unit every time I cut the grass with a leaf blower. It's clear.

[True Blue]

Possibly your system is low on refrigerant, frozen coil is one of the symptoms. Need an HVAC tech to check the levels. Hopefully Screw (John) will see this thread and be able to help you out.

[USAWIT2]

If the filter was that dirty the lack of air flow will freeze up the A-coil.
If it freezes up again after unthawing and changing the filter the unit is likely low on refrigerant.

[Das 5.0]

Just had this happen to me on Canada Day. All frozen up - thawed it out , replaced filter (wasn’t that bad) and hosed down unit outside. It’s been working mint since but still getting someone to have a look - if yours doesn’t fire back up it may be low on Freon. Also what ZR mentioned. The coil I could get to as it’s just had a few screws and tape - used a heat gun to thaw out the coil in the furnace. House went from 80 to 71 within 12 hours.... ahhh thank god....

[ZR]

On mine, guess previous owner either ran without a filter or let it go too long, inside / center of the A coil had a thick coating of debris n dust. While a bitch to access, only took a few minutes to gently vac clean. Well worth the effort in my case.

[JZ67]

12 hour update...the unit is blowing cold air and the coil is clear. I'm keeping and eye on it and my fingers crossed.

[Screw]

You should be ok
April filter & a Reno + usage this summer ya it would freeze

[redo75]

Shut ac unit down and look inside of furance . At the bottom of coil could have build up of dust. Vacuum coil GENTLY. Flush with water to wash off rest of dirt on inside of coil.

[JZ67]

It's been a few days and everything is working fine. I still need to check out the bottom of the coil. On the TDL for this weekend.

Thanks for the input everyone!

[ZR]

Hell yes.

[5.4MarkVIII]

not to hijack but thought maybe better than starting a new post.

New place has a oil furnace and an oil water heater. I know ive never seen an oil water heater before but there she is. its a rental and rental co wanted 1k to buy out. (estimate 10-15 years old)

question is the watehr heater feed its exhaust into the same flue as the furnace. I was under the assumption that this was not a thing that should be done. just want to confirm.

both the furnace and water heater exhaust pipes have about 1/4 inch holes drilled into the first elbow. not sure why that is.

input?

[IanGTCS]

Just a shot in the dark but are the holes to help with updraft?

Personally I'd replace the rental oil water heater with an owned electric. For that buyout you can buy one nice one or two cheap ones at Home Depot. And as an appliance guy is assume you'd know someone for an even better deal.

[5.4MarkVIII]

could be draft related though it does have a draft flap as well.

we have a connection threw a supplier for he "heat pump" electrics like Im running in our old house. thinking that might be the route to go.

[Screw]

1/4” holes likely for Combustion analyzing , why not go propane with heat pump ?

[5.4MarkVIII]

there is currently a NA gas line at the road it was never brought back to the house, my plan is to eventually trench it in and then convert everything to high efficacy natural gas. Im just trying to figure out what needs to be addressed right now. if anything


do you know if the code that doesn't allow multiple appliances to share a chimny. is that a "if it was done before the code its fine until you replace one" or is it a "change it now" code

[Screw]

Yes C vent can be common vented in a chimney
Would recommend an OBT tech do an inspection worth the $ and peace of mind if you plan on keeping it this season . Enbridge will bring the meter /line to the home with an application for gas so you don’t need to trench . Contact utility ask them if it’s feasible.

[USAWIT2]

If you can't get NG service consider going propane, not as cheap as NG but still way cheaper than oil

[5.4MarkVIII]

That’s the plan. Deal closes on the 31. Then need to look into garage build and getting either Natural gas or go lp if necessary.

[5.4MarkVIII]

More hvac questions. Lol.

I got an ecobee. And finally the transformer and relay I need to make it work with my old ass furnace came in.

So I can now have the furnace run when the upstairs is cold if the wood stove is off as well as if it gets too cold downstairs when the wood stove is on.
Other thing I’m wondering is there a way to also have the thermostat now control the fan alone. The fan will run when the furnace is on but if I want to only run the fan I have to hit a switch that is on the side of the furnace

I’m aiming I should be able to wire up a relay to have the thermostat control this.

Is there an easy kit for this?