Ghosts in the Basement

My wife usually goes to bed before I do. Like a sensible person, when she gets tired, she goes to bed. I prefer to fall asleep on the couch pretending to watch TV. This results in me finally showering and coming to bed after Yolanda has gone to sleep. Last night, when I got out of the shower i was greeted by four of the scariest words most married men can hear, “What was that noise?”

Turns out, that as I was getting ready to bed, and frequently running water, my wife kept hearing a strange sound from under our house. It sounded somewhere between a beep and a moan. After some experimenting, we realized the sound happened each time I turned off a hot water faucet. Since we’d just installed the new tankless hot water heater we had a likely suspect for the noise (that or the ghost of my crazy Aunt Flora).

Today I inspected the tankless again. I heard the noise faintly when I was standing in front of the unit but it was much louder upstairs. I called Noritz customer support and described the problem. The technician I spoke to immediately knew what it was. I never know in these situations to be happy or annoyed. I’m happy that someone knows what my problem is and confirms I’m not crazy. But I’m also annoyed because, if it is a known problem, why haven’t they done something about it?

In the Noritz tankless water heat we purchased, the NRC111, there are tiny servo-valves that cycle through a self-check each time the system shuts down after use. Normally that noise is unobtrusive. However, in some house, especially when in a basement or crawlspace, the vibration is communicated through pipes or structural members in the house and amplified. They suggested two mitigations; installing rubber gaskets between the unit and the mountings and installing flexible hose fittings between the copper supply lines and the unit.

I called the plumber at Bonney Plumbing and explained the problem and they agreed to do the mitigation when they come out to install the hydronics system.So two more items I’m also hopeful that when they spray the new insulating foam in our crawl space that the foam will absorb most of the sound.

So far, here’s the checklist,

1. Place a “T” fitting on the outlet of the exhaust pipe
2) Insulate the new hot water lines
3) The electrical box for the tankless system is missing a wall plate.
4) The exhaust vent on the outside of the house should have a gasket or seal.
5) Rubber gaskets under the tankless water heater mounts
6) Flexible hoses connecting the tankless heater to the water lines

Going Tankless Part 2 - The checklist begins

The plumber finished the installation of the tankless water heater today. The first surprise for me, is how quiet it is. I had some limited experience with tankless water heaters when I lived in Latin America, where they are common. I have distinct memories of hearing the roar as the water heater fired up when I started a shower.

When Andrew, the plumber, called me in to say we had hot water I followed him into the crawl space where the new water heater was installed. From the entrance I could not hear anything. I asked Andrew if the system was running and he assured me it was. I could not hear it until i was standing right in front of it.
Our new tankless water heater

Having read recently a number of anecdotes from tankless users about problems they had with the system shutting off in the middle of their showers due to insufficient water flow, the first thing I did was tour the house and turning on faucets one by one. It may be my imagination but it feels to me that the water pressure is lower in a couple of rooms. Bt the water temperature is perfect. I ran the shower in the master bath for 15 min. without any problems.

The previous owners of our home had installed a pre-circulation pump on a timer. This pump circulated hot water through the pipes in the house at key times so that when we turned on a faucet we got instant hot water. I had wondered at the additional expense. With the new system I see why. We have to run a lot of cold water out of the faucet before the hot water arrives. We can see this will drive our water usage way up and its painful in drought-plagued California to see all that water going down the drain. We’re going to need a solution for this problem.

Andrew and I walked around and inspected the job. We agreed their were a handful of things that yet to be done. Andrew promised he’d finish them up when he comes back to plumb in the hydronics. I borrowed a best practice from my software project management days and started a checklist. This will be a running list of pending items to be done before we’ll sign-off on the project (and before we’ll cut that final check.)

So far, here’s the checklist,

1. Place a “T” fitting on the outlet of the exhaust pipe
2) Insulate the new hot water lines
3) The electrical box for the tankless system is missing a wall plate.
4) The exhaust vent on the outside of the house should have a gasket or seal.

The Work Begins - Going Tankless

Today the project stared in earnest with the replacement of our standard hot water heater with a tankless water heater. The day began with a lot of decisions. Bonney Plumbing’s guy arrived around 9:00 a.m.. They had not seen our home before nor seemed briefed on the situation other than that the tankless water heater would form a part of a large project that included a hydronic heating system. I showed them around and we began to discussed installation options. It quickly became apparent that , while this might not be their first tankless system, it was their first installation of this model and so job one for them, read the installation manual. I pulled up the installation manual on-line so I could participate intelligently.

Old Faithful - Our old industrial strength water heater

The first decision was where to install the unit. In particular, should we simply swap the existing hot water tank or co-locate the tankless system with the new heat exchanger on the crawl space under the house. The considerations were, the maximum run allowed between the water heater and the heat exchanger, the exhausting of the system and the distance limits there, the draining of the condensation, the electrical connection and finally ease of access and lighting. We finally decided to co-locate the water heater in the crawlspace with the heating system. You may recall that one of the reasons given for changing to the lower temp, higher efficiency tankless system was that the shorter plumbing run would enable a lower temp system. We decided on a location near some support joists where we could run some two by fours to hang the system on. A previously installed light in that area provided convenient lighting. As a side benefit of this decision we freed up the old hot water heater cabinet for use as a closet in my home office.

With that decision made, we needed to decide; where to run the exhaust duct. It need to run to an outside wall, could be a maximum of 39 ft. (assuming there was only one elbow), and needed a incline back to the tankless unit so that condensation would run back into the system for collection rather than outside. We decided to vent behind the house under out raised deck. Electrical supply was easily handled by connecting to the circuit powering our Jacuzzi power jests in our master bath tub.

With these decisions made, Bonney’s guys got to work. I was hopeful the installation could be completed in one day. But as the afternoon wained I saw this would not happen. The guys called it quits when they realized they did not have the gas fittings required to finish the job. Fortunately, they’d had the foresight to leave the existing system intact and their plumber promised me we’d have hot water that night from our old system.

That evening Yolanda arrived for the dreaded wife inspection. She was less than happy with the location because the footing in that area is loose dirt and sharply sloped. Also, the light for that are does not come on with the wall switch by the entrance. One must cross in semi-darkness to that are to turn on the light for that area. She pictured late night emergency visits to the tankless water heater and was concerned that poor lighting and poor footing had the potential to make a hot water problem into a trip to the hospital if someone tripped in the dark. I see a small project in my future leveling the ground in that area, putting in some concrete pavers and potentially improving the lighting situation.

Next Yolanda and I discussed the placement of the exhaust. Yolanda pointed out that the exhaust would be directed straight into our poolside patio area. Which, in those 100 deg. days here, is the only cool outdoor place to relax. Hot smelly exhaust might not be the best addition. I promised to discuss moving the duct to the other side of the house with the installers.
Final note, turns out that, despite the best of intentions, something happened to the old hot water heater yesterday. Yolanda noticed the water was not as warm as usual when she took her evening shower. My showers follow hers and by then the residual hot water was gone. No hot water tonight! Lets hope the new system is up and running before tomorrow night.