High efficiency boilers and tankless
A code on the display and a cold house. Wall hung high efficiency boilers, combi boilers and tankless units, installed, set up and serviced by a team that works on the whole appliance, not only the pipe attached to it.
What it covers
The wall hung, sealed, high efficiency generation of gas equipment. Condensing boilers. Combi boilers that make both the heat and the hot water from one appliance. Condensing tankless water heaters. Installation, setup, the yearly service, diagnosis and repair. If yours hangs on a wall, vents through plastic pipe out the side of the house and shows a code on a display instead of having a pilot light, this is the page, whether it went in last year or the installer is long gone.
This page is about which kind of appliance, not which job. The other two split the other way. Water heaters is your domestic hot water, tank and conventional tankless. Boilers and heating is the system that heats the house, any boiler, with its zones and controls. This page is the modern condensing equipment, whichever of those two it happens to be doing.
This is the end of the trade a lot of plumbers leave alone. The pipe is familiar and the appliance is not, so the burner, the settings and the fault history get handed to a heating contractor, or the whole unit gets swapped for a simpler one the first time it acts up. Our team works on the appliance and the pipe together.
Worth being exact about the equipment, because the categories get muddled everywhere else. Viessmann and Weil-McLain build boilers, not tankless water heaters; Weil-McLain's hot water side is indirect tanks that run off the boiler. Rinnai, Navien and Bosch build both. All of it gets worked on.
What makes this equipment different
An older boiler draws its air from the room, sends its exhaust up the chimney and runs at one setting. The newer equipment is sealed, has its own fan, turns its output up and down with what the house needs, and pulls extra heat out of its own exhaust. That is where the savings come from, and it is also why it needs a different kind of care.
The vent is part of the appliance
Each model comes with its own venting instructions, and they differ between models from the same maker. A vent that is not set up the way the maker calls for rarely looks like a vent problem. It looks like a unit that shuts itself off on the coldest, windiest nights and runs fine the afternoon somebody comes to look at it.
It makes water, and the water has to go somewhere
This equipment produces a steady trickle of slightly acidic water while it runs, and that water needs a proper path to a drain. A blocked drain line is one of the most common reasons a modern boiler shuts itself down.
It has to be set up for the house
The burner turns up and down with demand, and it has to be adjusted to run cleanly across that range. A high efficiency boiler also only reaches its efficiency when the water coming back to it is cool enough, which depends on the radiators and on how the boiler is set. Installed and left at the factory settings, it can cost more to run than the old boiler it replaced. The savings are in the setup, not in the purchase.
The display has to be read
Each maker has its own fault codes and service menus, and the number on a Navien display does not mean the same thing on a Rinnai. The useful information, the recent faults and what the unit was doing when each one happened, sits behind a menu somebody has to know how to open. That is why a homeowner with a flashing display so often gets told to find a specialist.
What the job involves
- Sizing, and being willing to size down. New equipment often replaces something bigger than the house needed, and a boiler that is too big switches on and off constantly instead of running steadily.
- Checking the gas supply. A combi can need much more gas than the boiler it replaces, so the supply gets checked before anything is ordered. See gas lines.
- Planning where it goes. Where the vent can go out and where the drain line can reach decide where the unit hangs on the wall. Planned first, that is a clean install rather than a hose across the basement floor.
- Installing it. Mounted with room to service it, connected, and vented the way that model calls for. A tankless unit is set up so it can be flushed later without draining anything.
- Setting it up and testing it. Adjusted to run cleanly, set for the radiators or baseboard in the house, then run through a heating call and a hot water call before our team leaves.
When you need it
- A code or a flashing display on a wall hung unit
- It locks out and needs resetting to run again
- It locks out mainly in cold weather, or mainly when the wind is up
- Water pooling under or near the appliance
- A combi giving heat but lukewarm or swinging hot water
- A tankless unit that has quietly lost flow
- Switching on and off over and over on a mild day
- Running costs that never fell after the high efficiency unit went in
- A unit that has never had its annual service, or whose installer is gone
The annual service is part of the machine
A cast iron boiler forgives being ignored for years. Condensing equipment does not, and the makers call for a yearly service rather than offering it as an extra. What that visit involves, and how a tankless unit tells you its flush is due, is on its own page: heating system service and maintenance.
How Connerney handles it
- Licensed and insured. Licensed and insured in Massachusetts.
- The whole appliance. The burner, the controls and the fault history as well as the pipe. Nothing gets handed to a second contractor. Our team is certified with Viessmann, Navien and Buderus.
- Set up for your house. Adjusted to run cleanly and set for the radiators or baseboard it is heating, then run and checked before our team leaves.
- Owner run. Bill Connerney owns the business, answers the phone and books the jobs, and our team of experienced plumbers does the work. Rated 5.0 on Google across 20 reviews, and BBB accredited since 2018.
Questions people ask
- Why does it lock out on cold nights and run fine when somebody comes to look?
- Because the cause is often outside the unit. Exhaust being pulled back into the air intake when the wind blows a certain way, ice forming at the vent outside, or water collecting and freezing in the vent. None of that happens on a mild afternoon. The unit keeps a record of what it saw when it shut down, which is why reading that record comes before replacing anything.
- What does the code on the display actually mean?
- It is that maker's own shorthand for what the unit detected, and the same number means different things on different makes. What matters more than the code is the history behind it, which most units keep: the last several faults, in order. Write the code down, do not keep resetting it, and do not clear the history. Each reset can wipe out the information that helps find the problem.
- The installer is gone. Can somebody else take this unit on?
- Yes. The equipment is the same no matter who installed it, and the instructions for that exact model can be looked up. On a unit like that, the first visit is often the setup it never had: the burner checked and adjusted, the vent and drain line checked against the maker's instructions, the settings matched to the house, and the fault history read for what it says about the last few winters.
- Our bills did not fall after the high efficiency boiler went in. Why?
- Usually because it is not set up to run efficiently. A high efficiency boiler only reaches its efficiency when the water coming back to it is cool enough. Connected to radiators designed for very hot water, with the settings left at the factory defaults, it runs like an expensive conventional boiler. Sometimes it is also too big for the house. Both are setup and sizing problems, and both can be checked.
Related services
Where we work
Based in Natick, working across MetroWest Massachusetts.
Plus the surrounding MetroWest towns. If you are nearby, call and ask.
Call us, or request service
Tell us what is going on. If no one picks up, leave a message and Bill will call you back as soon as he can. If it is easier to write it down, the form reaches the same place.