central heating question

jhs14

stranger12 wrote: »

I got one of the honeywell digital trv to test as below

http://www.amazon.co.uk/gp/product/B0051UHFEI/ref=pd_lpo_sbs_dp_ss_2?pf_rd_p=569136327&pf_rd_s=lpo-top-stripe&pf_rd_t=201&pf_rd_i=B000KNE738&pf_rd_m=A3P5ROKL5A1OLE&pf_rd_r=1AJ6PW368E05RYN09DYZ

it is meant to be like thermostat and more accurate than my analog trv .

following that , I will install it for all other rooms .

If you go down that route I would go the whole hog and install Honeywell Evohome which looks to be a pretty impressive system.

stranger12

Too expensive at 285
I found the hr25 for £25 so £75 in total and wireless monitor for £50 . All in less than £125

SingleSue

booksurr wrote: »

1. unless you have a very sophisticated zonal system (which given your description is unlikely) covering each room that you can set temps for each independently then you have only 1 thermostat which controls the whole system so yes only when the hall reaches 20 deg will the system switch off and it will come back on when it drops below 20. That is why you do not set it at 20 if the other rooms will reach higher temps!! Didn't your parents explain such basics to you?

2. given the naivety of your questions it would be much better if you did not try to do anything to the system at all. Whether you simply add solution or clean the system before doing so depends on a number of factors so you should pay a plumber to do it for you

Just a little point, for those who have had this kind of central heating, it may seem a silly question. For those of us new to this kind of system, it is a little more confusing.

I have only just had the room thermostat system installed, before, everything was controlled via the actual radiators themselves and the timer in the airing cupboard. The heating came on for set times during the day and there was no way of setting it for a specific temperature or to come on when the temperatures were plunging.

My parents have exactly the same system as I had and would also find a seperate thermostat confusing, so they would have been unable to educate me either, so the posts on this page have actually confirmed in my mind how it all works and helped me...even if they have seemed a little silly to others.

Brilliant system though!

silvercar

I would start with the bedroom radiators on 3, the downstairs rads on 5 and the hall temp at 20. Then see how you go. If the whole house doesn't get warm enough turn up the hall temp to 22.

stranger12

I have a question,

here is my home setup

room thermostat in hallway and set to 15 degree

hall radiator off so the thermostat will never sense 15 degree to switch off or in another word boiler will be on always

If i leave the trv on setting on 3 which lets say it represents 21 degree and it will shut the water flow if the room is 21 degree for that specific radaitor , would I still be paying for gas ?

would my boiler use same amount of gas regardless of of how many radiators are on ?

sorry for the silly question, just curiuos . As I think ultimately if i need to save on costs the thermostat must be working so that it stops the boiler and no gas will be used.

G_M

stranger12 wrote: »

room thermostat in hallway and set to 15 degree

hall radiator off so the thermostat will never sense 15 degree to switch off or in another word boiler will be on always
correct. Boiler will constantly fire in an attempt to raise the temperature at the hall stat.

If i leave the trv on setting on 3 which lets say it represents 21 degree and it will shut the water flow if the room is 21 degree for that specific radaitor , would I still be paying for gas ?
Yes. You would shut off the water flow to that radiator (and other rads by same principal( but as explained above "Boiler will constantly fire in an attempt to raise the temperature at the hall stat."

would my boiler use same amount of gas regardless of of how many radiators are on ?
No. Fewer rads on = less gas.

http://www.miketheboilerman.com/how.htm

And don't forget hot water supply.

stranger12

when you say fewer rads= less gas , is that because the hot water boiled by the boiler will warm up the rooms quicker as there are less room to take the hot water in and cool it down (by rad) so in theory the boiler can be switched off sooner ?


otherwise the gas usage will be the same regardless of number of boiler. I mean the flow of gas to the boiler ?

I guess I ended up not saving by shutting the hallway rad as the boiler was on 24/7 which would have probably been cheaper to have the hallway rad on so potentially I could have heat up more rooms with less gas ?

G_M

stranger12 wrote: »

when you say fewer rads= less gas , is that because the hot water boiled by the boiler will warm up the rooms quicker as there are less room to take the hot water in and cool it down (by rad) so in theory the boiler can be switched off sooner ?

1) Water leaves boiler at X degrees and circulates.

If all rads are on, water at X ds enters rads and heat transfers from water, to rads, to room air. Thus water temperature drops as heat transfers.

Water returns to boiler at Y ds.

Boiler then has to re-heat the water to X ds

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2) Water leaves boiler at X degrees and circulates.

If all rads are off, water at X ds does not enter rads and heat is not transfered from water, to rads, to room air.

Water returns to boiler at (virtually) X ds.

Boiler then does not need to re-heat the water to X ds

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3) If some rads are on, some off, same principal applies to a lesser extent.

stranger12

That is what i was trying to say