Weather is the state of the atmosphere, describing for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloudy. On Earth, most weather phenomena occur in the lowest layer of the planet's atmosphere, the troposphere, just below the stratosphere. Weather refers to day-to-day temperature, precipitation, and other atmospheric conditions, whereas climate is the term for the averaging of atmospheric conditions over longer periods of time. When used without qualification, "weather" is generally understood to mean the weather of Earth.
Weather is driven by air pressure, temperature, and moisture differences between one place and another. These differences can occur due to the Sun's angle at any particular spot, which varies with latitude. The strong temperature contrast between polar and tropical air gives rise to the largest scale atmospheric circulations: the Hadley cell, the Ferrel cell, the polar cell, and the jet stream. Weather systems in the middle latitudes, such as extratropical cyclones, are caused by instabilities of the jet streamflow. Because Earth's axis is tilted relative to its orbital plane (called the ecliptic), sunlight is incident at different angles at different times of the year. On Earth's surface, temperatures usually range ±40 °C (−40 °F to 104 °F) annually. Over thousands of years, changes in Earth's orbit can affect the amount and distribution of solar energy received by Earth, thus influencing long-term climate and global climate change.
Surface temperature differences in turn cause pressure differences. Higher altitudes are cooler than lower altitudes, as most atmospheric heating is due to contact with the Earth's surface while radiative losses to space are mostly constant. Weather forecasting is the application of science and technology to predict the state of the atmosphere for a future time and a given location. Earth's weather system is a chaotic system; as a result, small changes to one part of the system can grow to have large effects on the system as a whole. Human attempts to control the weather have occurred throughout history, and there is evidence that human activities such as agriculture and industry have modified weather patterns
Studying how the weather works on other planets has been helpful in understanding how weather works on Earth. A famous landmark in the Solar System, Jupiter's Great Red Spot, is an anticyclonic storm known to have existed for at least 300 years. However, the weather is not limited to planetary bodies. A star's corona is constantly being lost to space, creating what is essentially a very thin atmosphere throughout the Solar System. The movement of mass ejected from the Sun is known as the solar wind.

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  1. surfsup

    Outside tap lost pressure since cold snap

    My outside tap has had really low pressure after the cold weather a few weeks ago. Its connected from under the kitchen sink, and can be isolated from turning a flat head screw type thing a quarter turn. Any help or advice would be much appreciated!
  2. M

    Weather comp settings at night?

    Hi How does the weather comp. work when you go to bed. If you have a lower temperature at night surely the next day the boiler then has to work that bit harder to reach the correct temperature for that day. What do you do?
  3. M

    Worcester Bosch Weather compensation

    Hi I'm new here so go canny with me. Hoping that someone can help with the following concerning weather comp, it is a Worcester Bosch comfort+ll control and in the menu it asks to set these values.These are what my thoughts are, are these correct. I am aiming for around 20c for the room...
  4. siricosm

    Weather compensation for cylinder?

    Does anyone know of a weather compensation unit that can be fitted to a cylinder? I have an Ideal Logic Max H24 which heats a thermal store. The boiler can take an Ideal weather compensation unit to raise the target flow temperature as the outside temperature drops, but the store temperature...
  5. R

    Weather comp (baxi ifos) with nest opentherm thermostst

    Hi all, I have just bought a google nest 3rd gen thermostat to be connected opentherm. I currently have the baxi ifos rather comp fitted. I was told that it was either one or the other, but baxi technical dept have said I can wire an opentherm controller alongside the ifos system. Boiler is...
  6. Desktop987456

    Viessmann weather compensation sensor

    If anyone looking to sale a spare viessmann outdoor sensor (pic attached), let me know via PM. Thanks
  7. M

    Heat Only Boiler + S Plan+ + Weather Compensation Query

    Hi looking for some advice here if anyone would be so kind. Our existing system consists of an Ideal Logic Heat H15 heat only boiler paired to a 180L Kingspan Tribune XE Unvented Indirect Hot Water Cylinder (this is the Dual Stat version). Zone 1 (Downstairs) consists of 7 Radiators + Plumbed...
  8. H

    Does Worcester Bosch 40cdi 2013 boiler support weather comp?

    Hi there, thanks for looking at this post. I've got a WB 40cdi heat only boiler which was installed around 2013. I've attached the model number. I'm trying to work out if there is a weather compensation feature which will automatically adjust the flow temperature down on warmer days? I don't...
  9. A

    ATAG OpenTherm and/or weather comp

    Hello everyone, I am new to the forum, thanks for having me. Tomorrow I am getting an ATAG i28C installed but, unfortunately, the gas engineer that will fit it is not an ATAG partner. Therefore, I spent the weekend trying to understand a bit more about what options I would have to control the...
  10. L

    Outside temperature sensor - weather compensation. Viessmann

    Morning all Viessmann Vitodens 200-W 35kW combi Outside temp sensor probably failed with boiler reporting incorrect temps. Corrosion on Thermistor. To replace the sensor, does it have to be the exact model showing on the manufacturer’s website, or would a slightly older (but same spec) sensor -...
  11. M

    Viessmann 100-W Heat Only and Weather Compensation

    We are a few months into our Viessmann Vitodens 100-W 19KW Heat Only boiler and it is working fine. We replaced an old 1999 Baxi. Our house is a 2 bathroom 4 bed detatched, built 1999. The engineer did not really know the Viessmann boiler and I am not convinced his approach of “turn everything...
  12. H

    Switch off Alpha weather prod sensor.

    I have a Alpha weather prod I wish to install. Can you put an on off switch in between the sensor pod and Alpha boiler. If yes what type of switch do I need. Thankyou
  13. L

    Advice on weather compensation for communal heating system

    Hello all, We have a Worcester Bosch GB162 100kw boiler in a residential block for the communal heating serving 12 flats. We currently sporadically manually set the boiler's flow temperature (e.g. 60 degrees when not too cold and 70 degrees when cold) on the boiler itself and use a timer to...
  14. S

    UFH/Rad combi boiler & Weather compensation

    Hello all I have a Worchester Bosch greenstar 32CDi combi with an S plan, 3port for UFH downstairs (4 zones) via manifold & mixer valve, & upstairs 4 rad system, with towel radiator always open for a bypass. I have a full tado system that is basically set to relay on/off when any thermostat...
  15. A

    Boiler weather comp being controlled with a optimising room stat

    Evening chaps. As the title says, can a boiler with weather comp run with an optimising room stat? I have a Glowworm Flexicom 35cx that can accept an external (outside) sensor, and the main controls is a Honeywell CMT927 optimising room stat. Reason I ask is I think they will fight each other as...
  16. S

    Upgrading Worcester Bosch 440 CDi ERP to weather compensation

    Hello everyone, I have a Worcester Bosch Greenstar 440CDI ERP installed in my cellar with EPH room thermostats, for 2 zones of heating in my house. These controls are a bit basic as they only allow one temperature and basic on/off times. I have seen the FW100 weather compensating controller...
  17. N

    Can the ballcock valve 'stick' shut due to hot weather?

    Our attic water tank (which is boarded in and not easily accessible) decided to stop filling up today... (we couldn't hear it filling up) and with the temperature outside reaching 32+ I am wondering if this might have caused a problem. The temp this evening outside has gone down to 21 degrees...
  18. L

    Boiler high pitched noise in cold weather?

    Hi, can anyone help me resolve this issue with my ideal logic combi Esp1 35. It is making a very loud high pitched noise whenever the outside temperature is cold, when either CH or HW is being used. For example, first thing in the morning on a cold day, run hot tap or turn up CH stat and the...
  19. J

    Weather compensator for Firebird Oil Boiler?

    I have a space heat only 26kw output Firebird Condensing oil boiler. I only use it for my homes space heating nothing else. Well insulated 80s renovated home. You can see there the boiler temperature stat is the simple white box. I recall about 10 years ago there used to be generic weather...
  20. J

    Trianco TRO Mk3 Not Firing up Off Timer When Colder Weather

    Hello everyone, I am looking for some help with this boiler. This problem has only just started in the last few weeks and only happens when it has been a long time (5/6 hours) between timer on settings and when it has been cold. Common time is at 06.00 when timer is set to come on for the...
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