help with cold air/negative pressure from Hearthstone Clydesdale

[ohiohearthstone]

Hopefully someone here has some pointers!
Old Masonry fireplace was a boiler type system (had makeup air tube outside-that was plugged with insulation upon install)
Chimney is on exterior wall of ranch house.
Hearthstone insert installed in October when it was still half way warm.
I wanted a 1 time install and seal job (because it has the removable baffle)
To my knowledge just insulation used at the damper (no shut off plate) and just the liner (no blanket).
Installer double checked that top plate is on the top and sealed.
I am getting a cold draft through the fireplace sides and top.
I am being told "live with it" by the installers. This is how they are (I don't believe it)
I was able to get a hold of someone @ Hearthstone who talked to me about negative pressure in the house, etc (he referenced some type of condar makeup vent like a dryer vent) *the last thing I need is an open vent in the room -its cold enough)
We have spend $4k on this deal and had I known this, I would of bulldozed the damn chimney.
I had the installer install some tin on the sides of the insert and we stuffed some insulation on the bottom of the blower.
This guy also noted that there was a mouse *live* in there. Now, we're just trying to figure out where the cold air is getting in and how to prevent critters.
The problem with this is that where the ss liner goes out at the top has a gap which lets any cold air from the chimney come right into the freaking house. (whose bright idea of a design?) Can I high temp a small tin piece here also that is safe.

The installers do not want to pull this unit out to check for leaks....just want to pass me off.
We decided to go with them because 1. we know them (want to keep things peaceful) and 2. wanted to keep business local

So my questions:
1. has anyone else experienced this type of issue
2. Would reopening the make up air tube alleviate some of these pressure issues? Does anyoen know where this unit come in?

3. Any suggestions/what can be done (guy at Hearthstone suggested a blanket/recheck cutoff plate/Condar unit

I really appreciate the help from anyone. At this point I'm dealing with either trying to
find an independent installer (at another $500 to try and fix this) or have to put 5 blankets on it and deal with mice.
I'm sure I can post some pics if it will help someone!

 

[Fsappo]

If the area at the damper is packed chuck full with rockwool and the liner at the top of the chimney is sealed the same way, below the top plate, I cant see where any other drafts are coming from.

I have no idea what a fireplace that was a boiler system means. Maybe you could explain that further.

 

[ohiohearthstone]

The old fireplace was a boiler type (had copper tubes inside the firebox) These tubes were connected to the rest of the electric based baseboard heat. Otherwise, this was/is a normal firebox. The more I read on this issue, I am going to ask my installer or get another contractor to pull the unit and install a pipewrap and sheetmetal damper closing to try to stop critters from getting in. FYI, there was no rockwool insulation packed around the pipe at the bottom (which probably should of happened also)?

 

[BrowningBAR]

Photos might help, also.

 

[ohiohearthstone]

Hey all, here are some pics and more details:
As you can see in the first pic of the house...the ash door compartment has been stuffed with Styrofoam/insulation and spray foam
Above that is the "make up air tube" that has been capped...no idea where this even enters the chimney...can not see opening inside it.
The house has a Geothermal unit (installed in 99..closed system...make up air ) from previous baseboard heat. Only changes to the system have been to install tin runs under the house due to mice chewing the flex duct. I also had them install a return vent (15 feet in front of the stove) to try and equalize air distribution in the house. AT night I get a pretty cold draft from this 8" flex return vent (flex and yest its insulated through a cold attic. The other return is like a 20" coil and it does not draft much. We get quite a bit of draft through walls and windows. (this draft would make me believe the whole negative pressure deal.
The other return is at the end of the house..but I still get quite of an amount of draft. It just so happens that both ends of the house is cold.
I know the walls have paper backed insulation and I was planning on doing more blow in this summer. (I would say it has 90% of what is required...just needs a top off .
I've been reading a lot about negative pressure.
Is there someone here that can point me in the right direction. I have NO fans running, no dryer running . I understand the concept of more air leaving....so it must come in... I've read the "open a window" open a door" but I just don't get the idea of trying to heat the outside....I would think you would want it tight? They guy from Hearthstone directed me towards condar unit (like a dryer vent .. i understand this would let air in but who wants to sit in a 32 degree room -if you dont have a fireplace going?
The house has a crawl space with several vents on the back of the house. It is almost 55 degrees under the house and it is almost as comfortable as inside the house. One change I did do this winter is to cut Styrofoam for the vents. (because those $30 self closers were obviously a rip off) I've been trying to install foil backed insulation in the crawl also to help with some heat loss issues.

I appreciate any help someone can give. We don't have much $$ and I'm just trying to help my mother have a warmer home. I'm pretty handy and can do stuff but just don't have the cash to do some kind of major overhaul... I enjoy winter but this year...it can be over any time so I can try and figure out what the hell is going on with this house... (the air is sure coming in to equalize..(but it's leaving from god knows where?

Should we have installers open the ash dump in the box and open the Outside air tube to relieve pressure...? but would'nt this just be like having an open window and freeze us out of the room...? so confused on what to do....

 

[oconnor]

Given that you are on a single storey slab, you likely don't have negative pressure issues unless you have large exhaust fans running. I do see ten or more attic vents along the roof, so it is possible that a lot of heat is leaving into your attic thru attic hatches and light penetrations - have a look for dirt trails around the edges of openings, and if you see them, seal these areas off. That will minimise any air loss thru the attic.

Most of what you are describing sounds like cold hearth syndrome, where the large mass of your brick chimney cools everything down, and when you open the stove, you get a down draft.

Sealing the top around the liner with high temp silicone will work, and you should look for any other cracks in the top as well as missing mortar in the chimney. As well, given you have a continuous liner to the stove, you can seal off the clean out outside as well.

Next, look into a block off plate where the liner passes thru the old damper of the fireplace - in the interim, some Rockwool insulation (most big box stores carry it - about 30% more expensive than fibreglass) stuffed tight around the liner at the bottom to seal the area around the liner from the room will add some relief. Rockwool isn't intended for use in high heat areas like around a liner during a chimney fire, but it will give you an indication of how a sheet steel block off plate can improve your situation.

Search this site for block off plates, and you will get lots of posts with good pics and drawings of how to build and install one. Not expensive if you can cut sheet steel yourself.

As for an outside air kit (OAK), if you decide on one, I would direct it out thru the wall of your chimney straight back - I assume that the air inlet on your insert is at the back. I would do the air sealing and block off plate first though - given that I'm not convinced that pressure is your issue, I'd wait on the OAK. If the sealing doesn't yield any results, then pressure may be your issue, and the OAK would help.

 

[ohiohearthstone]

Hopefully we are possibly having a new roof put on this summer. I'd like to get a ridge vent put in to replace all those vents.
Being the house is built with truss construction...things are tight in the attic to move around and check every fixture or wall board. As for the OAK..the white tube on the chimney was a built in one for the old fireplace..would this be able to be used.
The ash box is already sealed up. I guess I'm still trying to figure out the concept of having an open tube to the outside in the firebox. (I understand the concept of makeup air) I would just think this would continue to freeze us out.
The cold I'm getting from the stove is not just transfer cold in my opinion-because it blows. The top was recapped 2 yrs ago and re-pointed. I am looking at getting a blanket to insulate the liner as well and going to insist that a sheet metal block off plate is used at the damper to make a better than loose filled insulation. I know there is a hole somewhere because there was a mouse in there the other day. The tech tried to tell me that the mouse was in the house already and probably squeezed under the stove. Trust me there are plenty of nicer places to build a nest than in a cold firebox. Maybe there is some small mortar hole they are squeezing through or the ash door really isn't caulked shut (like the tech also said he did) It's not that I don't trust people.....but frankly I don't know if I can trust people anymore. I seem to always be the we have never seen that before, heard that before, thats new to us, live with it, etc type of guy. I've sealed up the stove with plastic today and managed to get the room back to 68 from a previous 58 with the stove uncovered(big change from "living with it as the tech said"
I want to go with a block off plate ....Is it pretty easy for another plate of some sort to block the opening where the pipe inserts in the center..so mice shouldnt be able to run in (I will put rope gasket under the stove). I really want them to pull the stove so I can caulk with rtv or some other fireblock caulk the inside of the firebox-anything that looks like an air gap so I can be sure.
My opinion is that a block off plate should solve 90% of the problem because air is getting in the chase somewhere -and thats the reassurance of the liner that should protect from a bigger issue.