Smart boiler change?

[boby733]

Hello,
We are currently buying a house, located in the municipality of Lentilly in the Lyonnais mountains, at an altitude of about 400 meters.
This is a house of 1965 compound full blockit is composed of a semi underground buried and a floor of 75m² habitable. The total area including the basement is about 180m ². After the energy diagnoses this house is classified as High energyIndeed, there is no interior or exterior insulation except the East facade with a slight interior insulation. The attic is lost and the former owner installed a year ago, 30cm of glass wool directly on the floor of the attic, between the wooden boards.
The windows have been changed for double glazing 5 years ago.
La slab between the basement and the floor is not isolated no more. There is a central heating with an old electric boiler powered phase, radiators are cast iron radiators so high temperature. The electricity bill is pretty huge, about 220 € / month. At each visit I made I checked if the walls were cold from the inside, which I did not find. We have several projects to save energy and money:
- Insulation from the outside, to be considered in a few years, the cost being still high.
- Interior insulation is not possible considering the loss of space.
- Changing the boiler to obtain a lower bill.
I'm posting this message to get your opinion on this boiler change:
After having studied the different solutions, the most judicious system seems to us to be an AIR-EAU heat pump, the pipes being already in place. We have not yet got a quote but according to an advisor the amount of installation fees included should not exceed the 10000 €, which would fit into our envelope work.
My question is:
Without adjusting the insulation, is changing this boiler by an air-water heat pump a good choice now?

I thank you in advance for your answers and for the time spent reading my post :-)
Boby.

[Obamot]

No thanks, no ads here for the chx pumps.
An electric heater - even with cast iron radiators - is NOT a central heating system (it is an abuse of language).

Make an ITE, it will cost you less than 8'000 € if you do it yourself (we find small scaffolding cheap and we spread the work in small steps depending on the weather ...). It is depreciated between 3 and 5ans by the heating economy achieved (if you do it this spring you will gain 2 heating seasons). And you save the price of your PåCs (only one is never enough for 180 m2). If you have it done by a craftsman it is worth it anyway.

The heat pump is to be avoided because the colder it is, the more you need it and the less interesting the COP is. And it does not exempt you from an ITE (good insulation ad hoc, otherwise you heat your town for free ...)

If you have not bought it yet, and you do not want to get your hands dirty, aim for the construction of a passive house, one in the other will probably cost you less in the long run. ..

ITE = External thermal insulation.

[boby733]

First of all, thank you Obamot for your answer!

I did not understand why an electric boiler + water circuit is not a central heating, what makes that system can not be considered as such?

Regarding the ITE, indeed we also considered doing it ourselves, getting our hands dirty does not bother us. However I was afraid of lack of competence especially for all that is window frame, door etc ... I would learn more details. There is also the duration of the project that can be scary, it is still a pretty huge job when it is done even? Or I see it more complicated than it is ... more than is it a surface started but not completed in relation to climatic hazards, including rain?

To return on the heat pump the surface to be heated is only 75m ², the rest of the dwelling does not have necessarily vocation to be arranged (for the moment) but of which I understand this system is to be avoided or then to combine with additional heating during very cold.

Finally, if I understand correctly you would do nothing for the current boiler? This is also the case for the heaters, which are therefore relatively old.

Thank you again for your feedback!

[Macro]

Personally if luckily there was a chimney next to the boiler ... I would swing a boiler used oil bought at a low price on leboncoin with a small tank of 1000litres for my first winters and I would put the package on insulation from the outside quickly..the connection to the current heating can be done easily with two hoses .. Then with savings made .. I would advise ..
Three-phase electric boiler ... This is something that was sold only to EDF agents who had bought a house with heating oil ca ...

[boby733]

Yes there is a chimney duct but not really near the boiler ... because a fuel boiler would be more economical than an electric boiler?
On the other hand I did not quite understand what you meant by "the connection on the current heating can be done easily with two flexible"
Another question, we will redo some of the electricity and we think switch to mono phaser and install a three-phase transformer to be able to power the electric boiler, is it according to a good idea or power consumption risk it explode?
Yours.

[Macro]

If your electric boiler is circulating water just reconnect the fuel boiler with plumbing hoses to screw on your fuel boiler. Very complicated. For your three-phase boiler .... There is very likely that it can be connected in single phase there is just the coupling of resistances to change. By cons I doubt that in single phase you can have an EDF subscribers powerful enough to feed your boiler and the rest of the house ... But me good I see it with my hands of handyman ... average warned ... C ' it is true that to go to get a boiler at a private house, to load it in a trailer to deposit it at home and to install it ... It is not at the immediate reach of the ordinary citizen not equipped ...

[boby733]

Yes indeed the handling does not seem complicated but as you say the steps to install it are not necessarily feasible without equipment and without real knowledge of this kind of system.
To sum up the ITE seems to be the priority above all else, remains the problem of the three-phase boiler ... is there any interest in replacing this boiler with a newer electric boiler and why not single-phase directly? In other words do you know if there have been technical developments on these devices to consume less? Obviously if the gain would be a few euros on the year the profitability would not be there before a moment.
I derive from the starting point, I should maybe create a new post? So many questions and possibilities during a purchase :-)
Thanks again for your answers !!

[dirk pitt]

it does not help to change the three-phase subscription a little more expensive but if you have to make changes to the boilers, it will not help.
even if you put money somewhere, do not put it in a change of energy because the consumption in kwh remaining the same, you will gain only the difference in € / kwh between two types of energy.
it is necessary to invest in an insulation to drastically lower the consumption and to leave for later the modification of the heating. since you have water radiators, it will for example be easy to switch to a pellet boiler.
small note: you say that cast iron radiators are at high temperature. it is the opposite: they are used at low temperature because in general they have a large surface (if it is old radiators with "arms"). at home, the temperature of radiators (cast iron) never exceeds 45 to 48 °

[raymon]

Of course you have to isolate but the fuel solution instead of electricity is excellent the price of fuel this winter was about 0,5 euros per liter and it is not tomorrow that the oil will be again at 100 dollars. There is about 11 kwh in a liter of fuel and some condensing boiler are close to a yield of 100%. Counting 10kwh for 0,5 euros (90% yield) we have 0,05 cts the kwh. I was given on the boncoin a condensing boiler it was simply dismounted and enter the sedan xantia! She was still in place, I got all the accessories that took us a big half day at 2 ..
Only in France are we still warming up to nuclear resistance.
https://www.leboncoin.fr/annonces/offre ... ne%20&it=1

[Obamot]

I did not understand why an electric boiler + water circuit is not a central heating, what makes that system can not be considered as such?

If you are absolutely certain that you have a water circuit, then yes, it is a central heating. I was referring to some VRPs who sell electric heating as if it was central heating under the pretext of accumulation in the radiators. It is an abuse of language in this case. So a thousand excuses I had not caught.

Regarding the ITE, indeed we also considered doing it ourselves, getting our hands dirty does not bother us. However I was afraid of lack of competence especially for all that is window frame, door etc ... I would learn more details. There is also the duration of the project that can be scary, it is still a pretty huge job when it is done even? Or I see it more complicated than it is ... more than is it a surface started but not completed in relation to climatic hazards, including rain?

Yes, I did say that we had to proceed in stages. In your case there is no choice, you will have to isolate the window panels with extruded PE, because you already have windows 2V asked.

But I would not hesitate for a second to make this ITE in priority. Why? Heating 220 € per month is a waste of 2'500 € / year wasted, in 3 you have paid back your ITE just with heating savings!

Because in the attic it's already done. Remains more than the front walls with LDR / LDV panels (compressed 200mm + vapor barrier) a small scaffold, the necessary protective equipment (masks, gloves, boots combination) a plastic tarpaulin to protect in case of rain and zou ...
On the market, all the fasteners already exist in PVC, you would only have to pay the finish roughcast or other posed on the lattice coming to clipper in front of the insulation ....

Have a quote from a small craftsman for work that you do not think you can do yourself. And if necessary he can help you in unforeseen situations. But apart from the question of scaffolding and window panels, it is much easier to install an ITE than an ITI (because the interior finishes require a lot of cuts and the type of interior finish can cost an arm. .)

Please note that if you use a qualified sealer, the salary in France is € 1'300.-, and there you are 2 to do it (in 1 months 1 / 2 is sold out)

but from what I understand this system is to proscribe or so to combine with additional heating during very cold.

Finally, if I understand correctly you would do nothing for the current boiler? This is also the case for the heaters, which are therefore relatively old.

How can you tell what your heating needs will be after ITE?
All I can suggest is to get started as soon as possible, because now or in no time we are going to the beautiful (and often dry). This is the best time to get started, right?
Then and only then will you see what is best for you. Right now what you've got is fine and there's no setup fee, no time wasted digging into it. You have better things to do => main objective in any case => reduce your consumption (regardless of the heating mode) => ITE

You have> 6 months ahead of you !!