Central heating. Bursts or constant? My results

Mazio_2

Have you thought about fitting ceiling fans they rotate the opposite way to summer and draw the cold air up and the theory is warm air down?

richardc1983

I would either try to install ceiling fans or get a heating engineer back out to "balance" the system. Balancing is where you adjust the flow valves and you pretty much start by closing all the valves down to probably one turn open and then the ones furthest away from the boiler will be the ones that are open probaly nearlly halfway, usually these are the upstairs rads in a house. Lots of info can be found on the internet on balancing radiators. THe aim to balancing radiators is pretty much they should all be really the same temp nice and hot but there is some links on the internet that say you should try to achieve a temp diff across the radiator of 12C. In my experience this can lead to problems and you can end up reducing the radiator output and therefore rooms get colder if you aim for the temp differencial.

Your best off balancing the radiators are by closing the valve down as much as you can but without this affecting the radiator temp (should still be nice and hot) as a rule the further u get away from the boiler the further open the valves should be. Try to keep all radiators as hot as the first radiator, its not important to aim for the temp difference, keep them all as hot as you can but closed down on the valve as much as poss. The temp difference really was a guideline for radiators connected in series, flow side was connected to the outlet (daisychained) so the outlet would connect up with next radiator in the line. OBviously if you had all the supply going through one radiator then by the time it had gotten to other rads it would have cooled considerably so as a guide it was appropriate to ensure that all radiators got equal flow of the hot supply. Nowadays this doenst need to come into it and its much simpler.

It can really improve system performance, I balanced my friends system for him as all the valves on all rads were fully open, whilst the downstairs rads were warm, they were not hot and there was not enough pressure in the system to get the hot water around the house to the other rads what your trying to achieve when balancing is pressure in the system to get water around the system. He found that he had to have his boiler flow temp (80C) on full pelt to get the downstairs rads hot enough to heat the rooms and the upstairs rooms most of the rads were luke warm or cold, now its all balanced he has found that he only has to have it on (66C) flow temp and the rads are red hot all the way through. If its a big house and you have a separate pump to the boiler consider speeding up the pump to move the water quicker. Once u have turned the valves down let the system level out for 10minutes or so and then adjust as you need.

Another thing to check is air in the system, bleed your radiators with the system turned on and warmed up, open the bleed valve at the top of the radiator and when water comes out you know it is bled.

Heres a couple of links to balancing rads...

http://forums.moneysavingexpert.com/showthread.html?t=334241

http://www.ebuild.co.uk/forums/messages/3322/6125.html



SOmeone made a point earlier of room thermostats. This is not nessasary at all considering you have individual thermostatic radiator valves that can control the temp in each room. If you was to fit a room thermostat then this would give false readings to the boiler and does not give you control over individual rooms.

WIth regards to temp readings. I work in heating, ventilation and air conditioning and the recommended room temp is 21C for living rooms, this is a temp that most people are comfortable with give or take some people may like a degree or two warmer. Bedrooms should be around the 18C mark.

The temps you quote are extremely low and if your not careful your gran could become seriously ill. You say yourself your hands are frozen.

You should be aiming at least to get the temps of the occupied rooms upto 18C.

Hope this helps and you manage to get your rooms warmer and your bills down, it is possible.

Kind regards
Richard.

rennysnell

ToTo_Man wrote: »

Our existing direct debit for both gas and electricity with E-on increased in September from £198 to £227 per month, but according to my calculations our monthly winter use of gas alone is in excess of £300.

Surely, something is wrong here? This is a very large monthly expenditure, yet your 'heated' room temperatures are extremely low - hazardously so, some would say. OK, you have a large house, and you live in a cold area, but still, this looks very odd to me. Is your boiler working correctly? - do you have it serviced regularly? (sorry, you may have said this, I don't recall). Has your CH system ever been flushed?

Frankly, you are so far off the scale, I suggest you have a heating engineer review your system. OK, costs money, but it may save you in the long run (as well as giving a decent room temperature for your gran - the whole nation is now watching this!).

espresso

rennysnell wrote: »

Frankly, you are so far off the scale............

You may well be right regarding scale. Perhaps the boiler/heating systems efficiency could be greatly improved by using some of some of these products here.

They really do work and can make a significant difference.

ToTo_Man

Based on the above comments, I will explore balancing.

Can someone please explain the following:

Does closing the return valves on the radiators (not completely closed of course) limit the speed at which the water returns to the boiler to be reheated? I am trying to ascertain whether keeping water 'static' in the radiators for a longer time before it returns to the boiler to be reheated will increase the cost efficiency of the boiler, or will the drop in temperature in the return pipe cancel out the gain in efficiency of the boiler not having to reheat the water as often? I hope my wording makes sense!

The two radiators which are most troublesome to fine tune are the radiator in my gran's bathroom (downstairs and closest to the boiler) and the radiator/towel rail in our bathroom (upstairs but still quite close to the boiler due to the pipework layout). Neither rad has a TRV.

The rad in my gran's bathroom is ESPECIALLY finicky and is the hottest rad in the whole house (and by hot I mean not being able to keep your hand on it for more than a second!). Took numerous attempts but I finally managed to get it down to a temp more inline with the other rads (still too hot for my liking though), which involves the supply valve being less that 1mm away from completely closed (honestly it's THAT sensitive to changes!).

Upstairs bathroom is less finicky but it's impossible to accurately gauge how far you are opening/closing the supply and return taps as even though the taps are 4-pronged they don't match up when both are set to fully closed so it involves doing it by eye. I'd say I've got the bathroom supply and return taps open less than a quarter turn out of a possible 3 or 4 turns. This temp is nice as any hotter and the towel rail is too hot to touch.

Are these two rads much more sensitive to valve adjustments because they don't have TRVs fitted, or is this merely a coincidence?

tomstickland

No no no, my mate who installs boilers says that having the heating on all of the time is cheaper. They even left it on whilst they went away for 3 weeks so they could save energy when they got back due the fabric of the house being warmer.

richardc1983

Totoman have u read my comments that I wrote out above.

The rads that are closest to boiler you mention it is about 1mm from closed, this is correct, this is how little you actually need some of them open to have them really hot. You dont actually really need them fully open. If your going to slow the rate at what the water returns to the boiler or gets into the rads overall this will improve the efficiency of the boiler as it is doing a better job. YOu have to think that if ur rads are red hot your boiler isnt having to work as hard to push the water round. Whether the water flows through fast or slow is still gonna cost about the same to run as the water is still gonna lose its heat, your not gonna slow down the rate at which the heat leaves the radiators cos thats something you ave no control over... its physics ya see!

ALl you can do is fine tune the system and get the best your gonna get from it. Dont even go down the line of "if i slow the water down it will be more efficient" cos in a way thats what balancing is, but your doing it to get an even temp across all radiators, they should all really be really hot as your grans radiator. So go round try to get this temp.

U mention they dont have txv, well this doesnt matter really, as long as one valve on 1 radiator that doesnt have a txv remains fully open you can balance these rads like any other radiator. If they are closed down to within 1mm from being fully closed then your not gonna be able to balance it any more so just go onto the next one, however make sure you leave at least one rad on the system fully open either on the return or flow side. This is so that if the txvs are not calling for heat the system can still have an unrestricted flow of water through the system, they can still be balanced though on the other valves.

Hope this helps.

ToTo_Man

richardc1983 wrote: »

Totoman have u read my comments that I wrote out above.

The rads that are closest to boiler you mention it is about 1mm from closed, this is correct, this is how little you actually need some of them open to have them really hot. You dont actually really need them fully open. If your going to slow the rate at what the water returns to the boiler or gets into the rads overall this will improve the efficiency of the boiler as it is doing a better job. YOu have to think that if ur rads are red hot your boiler isnt having to work as hard to push the water round. Whether the water flows through fast or slow is still gonna cost about the same to run as the water is still gonna lose its heat, your not gonna slow down the rate at which the heat leaves the radiators cos thats something you ave no control over... its physics ya see!

ALl you can do is fine tune the system and get the best your gonna get from it. Dont even go down the line of "if i slow the water down it will be more efficient" cos in a way thats what balancing is, but your doing it to get an even temp across all radiators, they should all really be really hot as your grans radiator. So go round try to get this temp.

U mention they dont have txv, well this doesnt matter really, as long as one valve on 1 radiator that doesnt have a txv remains fully open you can balance these rads like any other radiator. If they are closed down to within 1mm from being fully closed then your not gonna be able to balance it any more so just go onto the next one, however make sure you leave at least one rad on the system fully open either on the return or flow side. This is so that if the txvs are not calling for heat the system can still have an unrestricted flow of water through the system, they can still be balanced though on the other valves.

Hope this helps.

Hi Richard, thanks. So I need to keep one radiator in the chain fully open at both valves or just one valve? At the moment NONE of the radiators are set fully open at both ends. Perhaps that's why I'm hearing so many clicks and clanks! Also is it worth experimenting with the temperature setting on the boiler? It's set roughly between 90%-95% just now and heats until it reaches 78C and then clicks off.

richardc1983

All ur rads can be balanced, however leave one radiator with one valve fullly open, you can balance the other valve though. This is so that if the TXVS close down on all the rest one radiator still has a flow through it completing the circuit so to speak.

ToTo_Man

Merry Christmas everyone!

A quick update on the situation:
I've fine tuned all of the radiators again and have successfully managed to get my gran's bedroom and living room up to a temperature of 15.5C and 17C, respectively. As the rads have TRVs, this is regardless of the outside temps, i.e. on mild days the rads are luke warm to touch but on cold days like this they are hot to touch. So as long as the heating is on she is getting these temps consistently. Her rads are only set to position '2' out of a possible maximum of '5', so I am confident I could get her rooms considerably hotter than this, however she is happy with these new temps. I try whenever possible to have 1 day per week with the heating off to recoup some expenditure (i.e. I check the weather forecast the night before and make the decision based on that). If the outside temp is forecast 9C or higher then I keep the heating off and switch on the electric heaters in my gran's rooms and my parents put the gas fire on in their living room.


FWIW - The cost of having the CH heating OFF (i.e. the cost of just having hot water, gas for cooking, and the gas fire on for 3hrs in the evening) comes to £2.25, so it saves just over £10 to not have the CH on for the day. Not sure how much my gran's 2 electric heaters cost to run on thermostat for most of the day but I guess it will be less than the £10 saved on the CH....