Boilers, Radiators and Quotes!

[Tippon]

My uncle’s been a plumber and gas engineer for years, and I was asking him about this recently. I asked if it’s worth creating different heating zones in the house, and getting smart radiator valves, and his answer was that at the moment there’s no point.

The wireless main thermostat is great, because it can be taken anywhere. If you end up using a different room as your main room, you can just take it with you. As far as smart radiator valves go, you find that once you’ve figured out your comfortable temp for a particular room, you don’t generally change it. The idea of being able to tell the heating to switch on when you’re heading home from work is great, but if you finish at a regular time, you can just set the timer on the boiler itself. Even my ancient boiler’s got that  :yahoo:

[Richard]

Going even further off topic.

You can overdo the zoning as the company I worked for found out to their cost. OK it was in the Middle East and in a location that was very hot and very humid. they decided that not air-conditioning some spaces was a good idea as they did not need to be cooled. That was a bad idea. The air-conditioning also de-humidified the spaces; those hot humid areas without cooling and dehumidifying leaked damp into the internal walls which considerably shortened the building’s life. I have known similar in UK buildings though you do have to be a bit extreme with the abuse. Leaving spaces totally unheated can cause damp and mould issues. As an aside which illustrates the humidity level, the rats from the Ministry of Health compound next door to our site used to come over to have a drink from the condensation on my office windows. Watching them was not an entirely cute experience.

Dave, your combined energy bill gas and electricity is very good. I would probably be too embarrassed to reveal ours, but with three people always here and all three having significant health issues, both our electricity and gas bills are chunkier before combination than your overall bill. Being mid terrace will reduce your heat loss; though in addition to other aspects, our electricity bill will be affected by the use of an air-source heat pump for the conservatory.

It certainly pays to shop around, when my previous electricity supplier appeared to want to buy a swimming pool for the chairman at my expense, I shopped around and got a dual fuel deal for less than the ‘would have been the new electricity bill alone’ from the old supplier.

SWMBO requires a certain, consistent level of heating through the house so differential heating and over aggressive time control would only wear out the override function. Complex timers can be a nightmare. We can set every day to be different and the water and heating can run on different programmes. Good luck with setting that lot, it was hard enough to set everyday to be more or less the same. Beware, instruction books are not usually user friendly! I would rather not want to keep resetting that every five minutes.

[Dave Rice]

Thanks Tippon, that’s exactly what I was struggling to say.

Richard, we keep the doors of all the rooms open even if they’re not used much. They’re mostly bedrooms and so on the top floor and with heat rising from below I can’t remember when their radiators actually turned on (there is the new recommended amount of insulation in the loft and walls). That’s pretty much true of the living room on the middle floor too. The radiators in the kitchen and hall pretty much do the work for the whole house.

As for timers, when the weather gets cold enough the heating goes on and stays on 24 / 7. The thermostat in the hall is set at about 18C. It works for us.

[PlaneMan]

Checked the boiler at mum’s and it’s one of these, 34 CDi.

IIRC  the 29 CDi would have been sufficient but pushing it a bit when visitors descend, which is quite often, hence the 34.

[Ed P]

Boiler sizing also depends whether it is occupied ‘most’ of the time or if you and your partner are at work 5 days/week. Not much point in heating an empty house, so timers/smart phone controls come into their own. The former situation probably runs best without too much excess capacity. The latter needs a fast warm up so a higher heating capacity makes sense. However if you have smart phone controls you can f necessary over-ride the heating controls and again go with a heating system with a bit of spare.

Better to oversize a bit in either case, as I still remember visiting some friends in Marseilles during an unexpected really frigid cold snap — we all froze our butts off due to totally inadequate heating and 1cm gaps — windows, doors, just about everywhere.

[Richard]

So called high efficiency boilers are supposed to run with higher efficiency when operated at high load levels. If you cannot cool the return water down far enough before it hits the boiler then the condensing part will not do anything much. I was told that contrary to older practice over sizing modern boilers is not regarded as sound practice. This reference, at least in part suggests that over sizing the radiators while avoiding over sizing the boiler will give a better performance. The radiators will likely run slightly cooler to the touch and ensure the greatest temperature differential between the hot water being produced and the return water being taken in; https://www.aecb.net/forum/index.php?topic=1664.0

Your account of Marseilles really highlights the importance of draught proofing and insulation. Many modern light weight houses are quick to heat up as there is little substance to absorb the heat, but should have good levels of insulation – you hope. Other places with more solid walls may take a little longer but cycle the system less frequently.

Short cycling is to be avoided as discussed in this link http://www.home-heating-systems-and-solutions.com/boiler-short-cycling.html though I am not saying this is the definitive word on the subject.

As indicated earlier, we run warmer (with the hall thermostat set to anywhere between 21C and 23C) than many other houses. We have 24 hour occupancy and all three have medical issues. The new boiler has no trouble maintaining the temperatures we desire though we might have a larger floor area than some houses at over 2,000 square feet. When last checked the boiler was achieving a fraction under 90% efficiency.

Richard

[The Duke]

What you running their Richard a sauna? Our only comes on if the house dropped below 14. I’d melt in your gaff.

But we are all warm blooded, except the wife, it’s rare we close the upstairs window. Ours is a big fire escape window, so has been closed a few times this winter, but I know the kids haven shut theirs this winter.

House is currently 17 with no heating on. The the bedrooms will be a bit cooler.

[isdarit]

What part of the world do you live in with them quotes? how big is the house?  As for your boiler choice (Worcester) great boiler but I would not be averse to recommend the Baxi (10 yr gtee too) or the Vaillant and I cant believe I’m going to say Ideal too. All boilers now have become more reliable / efficient / eco friendly. Running costs cant be much in it think if you factor the purchase price to the running costs over the length of the gtee and any servicing costs you may change your mind ? also the plumber *will* be getting a discount on the boiler so haggle his tits off.

[JayCeeDee]

One of the best aids to a warm house was when we put reflective foil behind each radiator that was mounted on an outside wall. This made a huge difference to room temperatures with no increase in running costs.

[Tippon]

JayCeeDee wrote:

One of the best aids to a warm house was when we put reflective foil behind each radiator that was mounted on an outside wall. This made a huge difference to room temperatures with no increase in running costs.

Thanks for the reminder, I need to do this too.

Did you get anything special?

[Anonymous]

isdarit wrote:

What part of the world do you live in with them quotes? how big is the house?

West Midlands (Solihull). House is a terrace 3 bedroom house. Bedrooms are about 3.2m by 2.4m. Living Room is quite large so will need two larger radiators to heat effectively.

The fact all of my quotes have recommended Worcester Bosch I am comfortable with. Thanks for the tip on the reflective panels, will see if I can get that done in time for the radiators installed, rather than having to retro-fit it (easy enough, but preferable to do straight off I expect).

House will be occupied Weekend as well as in evenings. Not going for a fancy internet enabled system, though there may be odd occasions where I need to work late, so it would be useful to be able to override the system. Will pick up a Nest down the line I expect.

[The Duke]

<i>There is an argument I’m the Radiator world, one Side says you should put your rads under Windows, so around the exterior or your home, the other side say you should try and mount the rads in the centre of your house, if you have a core solid wall the better. </i>

I opted for option 2, and have 5 of out 9 rads, all big double ones in fact, on the one wall the center main wall.

When the heating is on they heat the wall up, so it acts in dissipating heat throughout the house and stays warmer longer.

It defo heats the wall up, but I’m not sure how much it adds to the overall effect. however, having the rads on one wall defo kept the cost of the copper down a fair bit when installed.

We don’t have a single rad on an exterior wall. But I’d defo have foil or some foil back insulation behind them if I did.

Also my biggest tip is, don’t get a fancy towel rail rad, just get a small rad and put a normal towel rail above it.

The towel rail rads are rubbish, they give off hardly any heat.  just get a proper rad that fits the space. They don’t look as good, but the rails are usless. Im sure most here will agree.

[Dave Rice]

Don’t agree with the towel (ladder type) radiator. Our two give off fearsome heat when they’re on.

No way could you keep your hand on them when they’re going full tilt.

Radiators are all about external surface area, the shape doesn’t matter that much.

What they are made of does – anyone remember the huge cast iron jobs in school? Probably took the whole of December to get hot and the whole of March to cool down. Sit on them after a wet walk to school and you’d steam, if you could sit on them for more than 30 seconds.

[The Duke]

My towel rail sucks, it gets hot to touch, as hot as my others do, bit the heat it gives off just doesn’t heat the bathroom well.

 

Llickilly a bathroom doesn’t really need heating in, given the bath or shower is a huge heater, and heats the room sufficiently, so when I you finish the room is warm.

[JayCeeDee]

Tippon wrote:

JayCeeDee wrote:

One of the best aids to a warm house was when we put reflective foil behind each radiator that was mounted on an outside wall. This made a huge difference to room temperatures with no increase in running costs.

Thanks for the reminder, I need to do this too. Did you get anything special?

It was just a version of THIS – all the DIY sheds had a version. It can be retro-fitted, almost as easily as beforehand.

[Ed P]

One tip (from bitter experience), thermostat controlled valves are NOT always good shut-off valves. Have a few isolating and drain points installed so you do not have to drain the whole system for what should be a small decorating job!

[Richard]

The problems with hanging towels on a rail above a radiator is that there is rarely enough room for enough towels and that after a year or two the constant presence of wet towels starts the radiator rusting. We replaced all of the radiators with towels rails when the bathrooms/cloakroom went through refurbishment and have not looked back. Seven radiators are on internal walls including the three towel rails, but that was the way that the house was laid out. The possible issue with radiators under windows is that people then hang curtains which allow the heat to go behind the curtain and heat the window not the room. A shelf above the radiator but below he curtain can assist with this issue as it will deflect heat away from the window and out into the room, or use blinds within the window recess. Radiators rarely if ever radiate, they heat mostly down to convection of heated air so taking account of the need for correct airflow when placing furniture pays dividends. Make sure that any radiators do not make furniture layouts more complex.

[Ed P]

+1 for Richard’s comments about furniture layout. Lots of furniture ‘needs’ a wall to sit against. I have recently come to the conclusion that ‘designer radiators‘ may have some merit in some circumstances. B-expensive however, but one might have a place on a lounge wall in order to get around furniture layout problems.

[Les.]

I am from the “Old School”, where things should be done right. I favour gravity systems, two pipe circulation, no pumps, radiators big enough, and LOCK SHIELD valves on all radiators. That includes towel rails. Problem is with lock shields, if you correctly calculated your radiator sizes, the lock shields need carefully balancing up. I don’t think I have EVER seen a properly balanced system other than my own. Today, the likely excuse is “No need, thermo valves fitted” – WRONG, they should always be balanced. If you are lucky, you may get a man with a calculator (tablet today) which spews out general sizes. If you sit down with pencil and paper, consider all aspects, you can design a system that WILL work properly from the get-go.

I hear about how efficient modern systems are, but the caveats are never mentioned. The oil fired boilers with pressure spray valves. These are set up to waste fuel, otherwise they will not burn the fuel completely. But I had better not go on about my vapourising burners again had I?

50 years ago, Which? did a booklet about designing your own CH (I think it was Which?). I still have an ex Ref library copy of  the 1959 year book of The Institute of Heating and Ventilation Engineering. Everything is in there, still in BThUs though, but that never bothered me.

Les.

[Spedley]

I have radiators in the centre of my house and it is dreadfull.  You can feel one side of your gody roasting while the other feels the cold like it radiates from the walls.  I get damp at the windows and on the walls.

I’m in the process of moving them all under windows on exterior walls.

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