Alternative to high bills?

markin

brewerdave said:

Astria said:

wild666 said:

lowering the temperatures on the boiler to 50 degrees for water and 55 degrees for heating

Has anyone actually compared the differences on this on both the gas and electric side?

Having a lower boiler temperature will very slightly decrease gas usage but it will also increase electricity usage as things like pumps and fans will need to be on longer to get to the same temperature, so will you actually save any money with raising electric costs?

Didn't want to upset @wild666's apple cart so haven't commented before - but I tried something along those lines with my gas boiler - running with too low a return temperature led to the thermostat never actually reaching the set temperature and the boiler constantly firing and shutting down and the pump constantly running; Bigger radiators only got warm. I suspect it'll only work if you live in one or two relatively small rooms with doors shut and the thermostat in one of the rooms. And the rest of the house can get pretty cold !!

Every system and house is different, Its just a starting point and will make huge savings 95% of the year, And yes you have to adjust It up in very cold weeks. 

brewerdave

QrizB said:

brewerdave said:

Astria said:

wild666 said:

lowering the temperatures on the boiler to 50 degrees for water and 55 degrees for heating

Has anyone actually compared the differences on this on both the gas and electric side?

but I tried something along those lines with my gas boiler - running with too low a return temperature led to the thermostat never actually reaching the set temperature and the boiler constantly firing and shutting down and the pump constantly running; Bigger radiators only got warm. I suspect it'll only work if you live in one or two relatively small rooms with doors shut and the thermostat in one of the rooms. And the rest of the house can get pretty cold !!

If you've got a smart enough boiler (& controls to match) it will do automatic weather compensation, turning the flow temp down when the weather is warmer and up when it's colder. You get the benefit of higher efficiency when possible, while keeping higher radiator temperatures when needed.

My boiler is 17 years old and not noticeably smart, so I do this manually. I've put a tick mark on the flow temperature knob to remind me where 50C (ish) flow temp is, and if the forecast is for subzero temperatures I turn the knob up.

My boiler is ~ 10 years old and certainly far from smart ! Same as you, I've marked the return flow control with a "comfort" setting from last Winter when we had all the downstairs radiators on, and at the moment it's turned further down - haven't shown the wife the control knob as she was complaining that it was too cold earlier this year ! Don't know what the actual return temp. was -but I suspect it was above 50deg C !

fergie_

Are you talking about combi boilers? Or storage cylinders too? The reason I ask is I believe the water should be at least 60deg to kill off bacteria.

Astria

fergie_ said:

Are you talking about combi boilers? Or storage cylinders too? The reason I ask is I believe the water should be at least 60deg to kill off bacteria.

Bacteria normally only forms when the water is stagnant, so if you are using the water regularly it shouldn't be an issue.

So if you have a hot water cylinder and don't use the water often (or go on holiday for example), it could be a problem and you should flush the system before using, or increase the temperature to 60c every so often to kill off any bacteria.

QrizB

fergie_ said:

Are you talking about combi boilers? Or storage cylinders too? The reason I ask is I believe the water should be at least 60deg to kill off bacteria.

Lots of people say this, but it's not true. 50-55C will kill legionella and all the other nasties you're likely to find in drinking water. Above 48C, legionella won't multiply.

From that link (original temps in F, my conversions in C):

The Dilemma:  Hot Enough or Too Hot

At 140 degrees [60 degrees C], Legionella die within about 30 minutes; at 130 degrees [54 degrees C], it can take as long as 6 to 8 hours to kill the bacteria; at 120 degrees [48 degrees C] ─ the recommended temperature for conserving energy ─ Legionella will survive but won’t multiply. Temperatures below 120 degrees encourage the bacteria’s growth.

However, it takes 10 minutes for water heated to 120 degrees to cause a serious burn and only 6 seconds of contact at 140 degrees. For young children or elders with sensitive skin, scalding is a serious risk.  But for anyone with a compromised immune system or chronic respiratory disease, Legionnaire’s Disease may be an equally serious concern.  Raising the temperature will kill Legionella but may burn a child;  lowering the temperature will prevent burns and conserve energy (the Department of Energy estimates that reducing the temperature from 140 degrees to 120 degrees can slash energy costs by as much as 10 percent) but it won’t kill Legionella.  What should you do?  Lower the temperature to prevent injury and conserve energy or crank it up to prevent illness?

Consider first:  If the high-end estimate of 18,000 cases of Legionnaire’s Disease annually is correct, in the United States, with a population of 326 million, the risks of contracting Legionnaire’s disease are minuscule and far outweigh the scald-prevention and energy-saving advantages of lowering the water temperature. In addition to reducing energy costs, the lower temperature will also slow the buildup of corrosive materials in water heaters and pipes, extending the life of those components.

However, health concerns in your household might well shift the risk-benefit equation in the other direction, with Legionella risks outweighing energy-conservation benefits and arguing for setting the temperature higher.

Anthrax spores on the other hand need 95C for 24h, but if you've got anthrax in your water you've got bigger problems.

matelodave

If you are really wound up about the possibilty of legionella, then increase the temp to 60 degrees for half an hour a couple of times a month - much more energy efficient than keeping it at 60 all the time.

BTW chlorine kills legionella and uk water is chlorinated so, unless you are storing lukewarm water for extended periods I shouldn't think that most people have many worries about catching legionnaires disease from their domestic water system and I'd think it was nigh on impossible if you've got a combi boiler or non-vented hot water tank

It's mainly institutions like residential home for the elderly, hotels and hospitals with large and complex water systems or air conditioning cooling units who might a have a bit more of a problem and generally thats where the HSE guidance is directed rather than at 27 Acacia Avenue in the suburbs.