Best Of
Re: Help with short cycling on a Weil-McLain GV-5 Boiler
Have you ever had a professional maintenance service? it is on page 19-20 of the manual
You will need a meter that measures micro volts and micro amps for testing a flame signal. Not a normal tool for the homeowner. And I have rarely used one because I can usually find if the flame signal is there by other methods. If I suspect the flame signal is the problem, I clean the flame rod (not in your case because that boiler has no flame rod and uses the HSI for the flame sensor). ALSO the HSI is very fragile and will break if you try to clean it, The burner cone can be cleaned, and should be cleaned if there is a lot of debris or carbon build up on it. It should be replaced if there is any metal missing.
Another fix for a poor flame signal is to run a dedicated ground wire from the HSI mounting screw to the grounded mounting screw on the control. Look on the control for the mounting screw that has a metal connection the mounting screw touches.
Re: Tankless heater proximity to gas meter
Let's just go back to square one here.
@motomars , could you find the relevant section of the code? You said "[you've] read somewhere that the meter must have a 36 inch clearance to a combustion source". Words matter. A lot. is it the meter, or is it the regulator? If it is the meter, that's pretty unambiguous — and a tankless heater is indeed a combustion source. Since it does not apparently specify where on the meter the measurement is to be taken from, the only meaning (at least the one I would have enforced) is from the nearest point anywhere on the meter to the questionable clearance. Or, in simpler terms, there must be a clear distance from the ignition source — which I would have interpreted as anywhere on the tankless heater — to anywhere on the meter of at least that 36 inches.
Re: Tankless heater proximity to gas meter
The blocking distance seems clear cut enough given that you know where to measure from. The fire concern with the regulator being outside is what I'm unsure of. The regulator seems to be the primary fire concern and a 36" radius from the vent is very clear but maybe the meter itself is also a fire concern and for simple rules the distance is same, 36". 36" from the center of the supply pipe union connection or the meter body or any edge? The closest ignition source in a tank-less heater might be the pcb board relays on the far side 36" away where the measurement starts. Inspectors have discretion to look at it and ok what they determine meets the intents of code.
Teemok
Re: Tankless heater proximity to gas meter
There are two completely different considerations here — which may be part of the confusion. The fire protection people are, understandably, concerned about the distance from a regulator vent to an ignition source. However, the meter regulation isn't concerned about ignition — it is concerned about maintenance.
As I read the initial the concern is about the distance from the meter to — in this case a tankless heater. Whether it's a tankless heater or not, as I read the code, makes no difference. You need three feet clearance around the meter. From anything except possibly a wall in back of it.
Re: Tankless heater proximity to gas meter
From my reading that outlet is considered an ignition source and must be 36" away from the meter. Any switch, relay, outlet or device with a spark igniter would be an ignition source. All the wording says "meter" and doesn't mention or differentiate from the regulator vent. On some diagrams the supply riser pipe seems to be the center from where 36" is measured and not the the meter or regulator itself. That said here's a picture provided by PG and E showing a 36" radius from the regulator vent outlet. Confusing. If your regulator is outside and the meter is inside there might be different rules. Check with a local authority is my advise.
Teemok
Re: Solar water heater Drain back evacuated tube
Hi @Teemok , My understanding of the conventional wisdom for household hot water use is 20 gallons for the first person and 15 for all others. Still, measuring hot water usage we've found that it can change by nearly an order of magnitude in different households. That's part of why I try first to reduce the load. People have always liked 1.5 gpm showerheads if they're well designed. They can make up for old, clogged up plumbing. I recently did a job where I was allowed to install 1/4" tubing from a manifold for the distribution. It takes no more than six seconds to get hot water, and the short runs have it in three. There is a lot we can do to make things efficient without sacrificing comfort. Or we can build monsters 👹 I've dealt with my share of those too 😑
Yours, Larry
Re: Solar water heater Drain back evacuated tube
@Larry Weingarten I wonder if 15gal. is enough? I guess it all depends on the clients intention and the end users expectations. While I have lived using 15 gallons or less of hot water a day, asking people to be that frugal here is an affront to their freedom to consume. A big no no even here in crunchy Nor Cal. I agree with the unpressurized storage and high coil HX approach. That could feed a 120 gallon tank with a mixer that's backed up by a cascade of 199K tank-less heaters. Could even low coil the big storage tank so that if the sun goes down or away and the big tank is too cold the tank-less could bring it up to a min. temperature for the next mornings peak load. And this is how I start to build a monster. 😁
Teemok
Re: Solar water heater Drain back evacuated tube
Hi, Just some basic math… Twelve apartments with two people each, or 24 people. At fifteen gallons of hot water per person per day, that's 360 gallons, or three times the storage you have now. One approach would be to install an unpressurized storage tank of 500 gallons or more and put a large coil in the top of the tank as a preheater for your backup storage heater. This likely wouldn't be inexpensive. I agree with @Teemok that unless you can adjust the owner's expectations to line up with reality, this could become a nightmare.
I like solar thermal and have been doing it for about 46 years, but to function, it MUST be simple and designed for the people who live with it. In this case, I think I'd start by looking at what could be done to make the hot water delivery system more water and energy efficient.
Yours, Larry
Re: Solar water heater Drain back evacuated tube
Hi Mike,
If tossing best logic to the wind and doubling down on thermal is the unalterable will of the investor, so be it. I think if are they willing to fully understand it, monitor it and maintain it themselves, it could be a good thing.
Is the money worth it for you to be involved? The risk to you is: Can you make a system meet the needs in almost all conditions? Will you be expected to maintain it? Will the customer at some point in the life cycle expense of the system realize that the whole effort was ill advised from the start? If that happens, will they find you at fault for aiding and abetting in creating the creature they invested in? Stating it up front in writing that it's "not wise" and getting it signed before hand doesn't prevent the future unhappy customer syndrome.
12-2 bath units all linked with a recirculation system?
High volume daily use makes for a best payback scenario but substantial storage is necessary and that's not cheap in materials or sqft-age. If it's a mission critical hot water system, full backup capacity is a must. Double investment. And the two systems need to play well together to make the solar payback. Then there's parts failures, clouds, hail, dust, roofing and heat dumping.
Think hard about it, it's going to be primarily a heart thing. Logic is necessary but secondary only to make it function. I don't think any logic will make it a simple, reliable and good investment. It's the free panels trap. It has to make sense if the panels are free right?
Teemok
Re: Solar water heater Drain back evacuated tube
Around me you can pretty regularly pick up solar hot water collectors on Craigslist for free.
When you consider the cost and complexity it makes more sense to put electric panels on the roof and use electricity to heat the water.
I know that's not what the customer wants, but sometimes what the customer wants is not in their best interest.
