Alternative to Gas Boiler ?

Is it possible to achieve this if I just turn down my ( non condensing ) heat only boiler setting, once the house and hot water is up to temperature?
An on/off boiler does not save or use any more energy if set high or low, set high when it switches off more heat lost through flue, set low it switches on and off more often, it may however effect the hysteresis.

The cooler the radiator the less heat it puts into the room, so the longer it takes so the less chance there is to over shoot, but also the longer it takes to raise the temperature of the room.

This is the problem with smart controls and geofencing, we want the house nearly to temperature when we get home, and the programmable TRV heads I use had way over the top anti hysteresis software, so set to 20°C at 7 am and it did not hit 20°C until 11 am, set at 22°C at 7 am and 20°C at 8 am and 9 times out of 10 at 20°C by 8 am.

If start temperature was 16°C it would soon get to 18°C it was the last 2°C which caused the problem.

So this house has on/off boiler and 9 programmable TRV heads, with a modulating boiler no problem, boiler does not turn off so as the TRV starts to open the return water cools and the boiler increases output, but with the on/off boiler the circulating water is fluctuating in temperature, and also needs a wall thermostat to turn it off, which means the pump also stops, so the TRV heads need to be slow acting or they would never stop adjusting, so we are back to "Compromise" and the whole of the central heating is a compromise.

Yes you can have heat pumps and Myson I-vector twin core fan assisted radiators that can keep the room spot on just like your car, selecting heating or cooling as required, but then there is a lot of waste, using single matrix and swapping the heat pump summer and winter to heating or cooling makes sense, a boiler can only heat, a heat pump can heat or cool, and if the same radiator is going to heat or cool, and it does not change position at ceiling height or floor height then there is only one option, fan assisted, it does not matter where it is located even behind the settee it can still circulate the air and heat and cool.

At the moment the I-vector radiators are expensive, but when we all want them, I suspect the price will drop, and like the consumer units when the IET/BSi changed the rules, they became available as split with RCD protection where not made before, so we will see fan assisted radiators becoming the norm. However the split consumer unit came in around 2008 and today we still have many houses without them, and those who embraced the change, are now having to change them again as they are plastic.

Toyota pioneered the idea of just in time, OK it was for materials deliveries, but it has paid off, it is simply no good trying to plan ahead, who could have planned for 2020?
 
Sponsored Links
An on/off boiler does not save or use any more energy if set high or low, set high when it switches off more heat lost through flue, set low it switches on and off more often, it may however effect the hysteresis.

No matter what the temperature it is set at the boiler loses more heat through the flue when it is running than when it is not, same with irradiation losses. Set low it rather depends on it's range of modulation matching the current load that determines how often it switches on/off.

The differences are all so minor and the fuel, NG, is so cheap.
 
The differences are all so minor and the fuel, NG, is so cheap.
Yes I hear them debating at work how the boiler should be stoked to get the most economy, and how the steam should be controlled, notching back etc. And the old guy simply said yes worth it with a big engine, but the difference with a small narrow gauge it likely one shovel full of coal, and more important to ensure you don't run out of steam, which is easy to do.

However there is a big difference between engines on how much coal to travel the same 8 miles.
 
We have all those except underfloor heating, its all rads, but yes thats interesting if its a possibility with radiators.

As a test, you can turn down the CH temperature on your current boiler so the flow temperature is what you’d get from a heat pump (maybe somewhere between 35 and 50 C) and see if the house is still warm enough on a cold day. If it isn’t, you would need larger radiators.
 
Sponsored Links
As a test, you can turn down the CH temperature on your current boiler so the flow temperature is what you’d get from a heat pump (maybe somewhere between 35 and 50 C) and see if the house is still warm enough on a cold day. If it isn’t, you would need larger radiators.

Mine is and yes it is absolutely fine at that.
 
Wouldnt worry about gas boilers being phased out. Currently this is only for new builds and theres no suggestion that gas boilers will become obsolete on existing properties. Gas remains the most cost effective method of heating your home.
 
does your boiler support direct input rather than a guessing dial? How do you know what the actual flow temp is rather than just guessing. I know as the boiler controller tells me

No,it is not opentherm or load compensated, the hall roomstat is just on/ off. There is no display of flow temperature, there is just a knob to set boiler temperature, 60 - 80 Deg C I think. ( It isn't condensing., and doesn't modulate as far as I know, it's just on/ off.) Turning this down does make the radiator temperature lower.
 
Last edited:
As in natural gas to be replaced with hydrogen. Hydrogen has a higher calorific value than NG but would work in the most modern of boilers. Until the hydrogen creation, storage, distribution and infrastructure is in place, NG will remain the primary use. You are good for at least a decade.
Boilers are not expensive these days (its the low IQ NVQ 2's that put the prices up) but one thing that saves huge sums of money is low temperature heating (again, the average NVQ 2 Wil have no idea so don't annoy yourself by asking one) . There are combis that have the option of selecting a low or hot temp (based on room temp) and use both methods. If the house is really cold, use the "room temp" setting to get the heat up then switch to low temp flow for background. The gas usage savings are dramatic, typically reducing gas consumption by 40% plus as a minimum. You might also consider opting for splitting the system and have DHW through a tankless water heater and a combi for heating. The combi can then also double as an emergency DHW supply. Combined cost of 2 units is less than a "big brand overpriced German product"


Do all combis have the room temp / low temp facility? That sounds a good system, do you have to switch it over manually then ?
 
I'm not talking about modulation of the boiler. I can choose to operate mine at anywhere between 35 to 80 degrees by selecting a value. 6 bedroom detached house yesterday cost £1.10 to heat and provide 2 baths and 2 showers. The heating was on for 10 hours

If the cost excluding standing charge was £1.10p that equates to approximately 27kW, that's pretty good for 10 hours of heating in a 6 bed house, 2 baths and 2 showers.
 
pretty good! I understand the physics of latent heat transfer but I had no idea to what extent the consumption and cost impact would be. Heating circuit flow control is the way to save huge sums of money

Well latent heat cannot possibly give you the 40% saving you've mentioned earlier but comparing a new system to an old can possibly give you that if the old was really poor.
 
eh? you should have an understanding of the basic concepts of science before you quote a wiki page...WTF has mass in relation to gas got to do with anything discussed here?
I'd be surprised if I don't have a better understanding of science than you do, and not just the basics. No wiki, I just confirmed the CV of hydrogen in Perry, density ratio is trivial if you have knowledge of molecular weight and its significance.
In #3 you didn't say whether the higher CV of hydrogen was by mass or volume. To check the gas pipe size if converting from nat gas to hydrogen the CV per unit volume is needed, and on that basis hydrogen does not have a higher value than nat gas.
 
I have a hatred for NVQ level 2's who call themselves engineers when 99.99 recurring could not pas a key stage 5 maths and english test. These people are the principle reason the UK is in the dark ages when it comes to water heating.

Probably fall into your hatred bracket then, I’m NVQ level 3, probably couldn’t pass key stage 5 maths/English, but call myself a gas engineer. Although my title at work is different.

Do I care - no, I don’t.
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Back
Top