replacing gas boiler in gravity system with electric Air2H20 heat pump

talals

is it possible to replace an old gas boiler for a gravity system with a modern electric air to water heat pump? if so is there a good contractor in Bay Area to do this?

Jamie Hall

Maybe. And maybe not. But nit will be a lot of very skilled work even if it does work. I presume by "Bay Area" you mean San Francisco, California? Up my way we think of Cape Cod Bay... the only person I know out that way is @RayWohlfarth , and I don't know if he is really in that area or just nearby -- or if he would be willing to take a look. You can PM him -- click on the name.

hot_rod

Thus journal has some good info on a conversion like that

If you are in the San Francisco area
Skaates Inc is a progressive radiant specialist out that way

https://www.caleffi.com/sites/default/files/file/idronics_25_na.pdf

leonz

talals said:

Is it possible to replace an old gas boiler for a gravity system with a modern electric air to water heat pump? If so, is there a good contractor in Bay Area to do this?

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Is your system an overhead gravity hot water heating system or a bottom fed gravity hot water system?

If you have a gravity hot water heating system that is working and not leaking why even consider this?
You are using gravity, thermal mass and simple physics to heat your home.

Having the boiler cleaned and the gas burner system cleaned/upgraded may be all that is needed.

Have you had a heat study done to see where you need to reduce heat loss?? adding insulation and replacing windows and doors and adding hot water storage. You will gain much more by increasing the amount of thermal mass by adding hot water storage on the return side of the boiler.

You will gain nothing other than another monthly expense during the heating season.

If you have the extra space in the basement you will save much more money by installing one or more pressure tested insulated hot water storage tanks that can be installed in the sump header pipe next to the boiler.

A good example of this tank is the 490 gallon New Horizons rectangular fully insulated hot water storage tank as it is small enough to pass through a standard doorway or down through a basement entrance Bilco door. This tank is 30" wide by 72" long by 60" long and is insulated using rock wool.


Adding thermal mass(water) is just like keeping money in a savings account.

ethicalpaul

> You will gain nothing other than another monthly expense during the heating season.

I think this is not accurate. The boiler is reportedly old, although we don't know how close to failing it is, it will definitely fail.

Also, you will gain the efficiency of moving the heat instead of creating it, which is significant.

The math isn't easy, but it's very doable to determine the benefits and costs of this system, but to say nothing will be gained is wrong.

leonz

We will disagree, This heating system is an open system operating with low pressure and has been since it was installed if the system is truly a gravity system.

When a heating plant can be disabled by a clumsy repairman ( in my brothers case) or a voltage surge, brown out or lightning strike on local 4KVA single phase power lines and cannot be repaired easily what good is this heating plant in the middle of a below freezing outage??????????????????????????????????????????

The homeowner may be being over sold by trying to install a brand new system that probably is not needed anyway if the boiler is intact and not leaking and gravity heating systems that are 100 years old are still working to this day almost silently with simple care.

We have no idea how "old" "this" boiler is and it may only require simple maintenance to improve its efficiency and if a heat loss study is done I am sure the home owner will save even more on heating bills
if it can be shown that a quicker return on investment can be had with more insulation, new windows and doors if needed without destroying a boiler that is intact and not leaking and the gravity hot water heating system he has.

I was screwed over when I was told my old 1953 avco lycoming boiler was leaking and I spent a
great deal of money replacing it when it only needed a minor repair as I was told when I gave it to a friend.

I have to disagree with you as the system owner has hot water for thermal mass and radiators that are either cast iron or steel tube and may simply need to be improved upon by simply tuning up the system having a heat loss study done and adding a large storage tank to increase the amount of thermal mass for the heating system.

Replacing one system for another or installing it to heat or cool is fraught with issues like a possible fried circuit board AND as I was told by my brother a replacement for the circuit board was not in the United States and had to be imported from Japan for his mini split system.

If a system cannot be maintained by having a system for maintaining an inventory parts in the country
where they are being installed I have to ask what good will come of it???

In the case of the local Habitat for humanities homes all I can do is shake my head as these systems can be disabled in less time than it takes to see a heartbeat as it only takes is a lightning strike to destroy electronics or a compressor and blow a gas line and boom!, Bobs your uncle, and well now, I need to buy a herd of milk house heaters to have heat.

ethicalpaul

> We have no idea how "old" "this" boiler is

Exactly, so how can you say that replacing it is a bad idea? At least Jamie said "maybe"

heathead

Might try reaching out to Alan (California Radiant) Forbes.

leonz

ethicalpaul said:

>
We have no idea how "old" "this" boiler is exactly,
so how can you say that replacing it is a bad idea?
At least Jamie said "maybe"

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Better yet how can you state it should be replaced without knowing its actual age, condition or whether
or has a weld or casting that has gone bad?

A local steam licenced plumber is what he or she needs for an honest examination, physical inspection, boiler cleaning, pressure test and a heat loss study.

ethicalpaul

Well since no one said the boiler should be replaced, I'm not sure what you mean.

I did say the math should be done:

The math isn't easy, but it's very doable to determine the benefits and costs of this system, but to say nothing will be gained is wrong.

Hot_water_fan

As always, it’s not a binary and the gas could be kept as backup.