Best way to deal with wrong radiator that was installed

moneyistooshorttomention

When I first bought this house I had the boiler swopped and some of the radiators replaced.

I noticed at the time that they had installed a radiator that wasn't powerful enough in the kitchen and had them swop it to a more powerful one (ie more btu's). I was forever having to switch on a fire too until they swopped it for correct one.

I've read all the stuff since about how firms calculate the btu's a radiator should be (according to how many exterior walls/windows/etc).

The main bedroom also has a radiator that isn't powerful enough installed by them - but that is proving workable with - as I keep the bedroom cooler anyway. That radiator wouldnt work if the bedroom was used as a sitting room for instance - but will do as a bedroom one. So, though it's the wrong one, I don't see me changing the usage of that room - so am inclined to leave that be.

The hallway and study ones were installed by someone different and they are powerful enough.

That leaves the sitting room one installed by the first firm - and it isn't powerful enough. They obviously didn't work out the btu's and/or size the radiator would need to be properly - bearing in mind it is a sitting room/has two large windows/two exterior walls/is the size of a "through lounge". So it's a double fin type one and size is 122cm long by 65cm high. Not sure whether it's wrong choice because of being too small or because of inadequate btu output - quite possibly it's both.

Wondering what my options are here - as I didn't realise in time to get the firm to swop that radiator as well for the "one they should have chosen in the first place". I expect to use radiators only for heating and not have to use my supplementary fires (they are for use only if the central heating isnt on imo) - as I have planned my house to be as trouble-free as possible to live in in all respects.

1. Should I go through expense/hassle of getting in another firm to swop the wrong sitting room radiator to the one Firm 1 should have chosen in the first place

2. Annoyingly have to use a fire as well as the radiator in sitting room

3. Alter the house thermostat to 23C (instead of "my" 21C) and it should "click in" more often to warm up the sitting room radiator than currently. Which would mean switching down the "volume" on the other radiators - so they don't warm up too.

I'm leaning to option 3 and can I assume that would "work" (ie have all my house at the temperature it should be) and, if so, would it cost me more on my fuel bills having that house thermostat set 2 degrees higher than my choice or would that be counterbalanced by switching the other individual radiators down?

DaftyDuck

If you radiators need balancing, so all output the maximum level of heat they should, then you should do that anyway. Turning down radiators in other rooms using the lockshield (not the thermal valve) would achieve this without lowering the temperature of the other rooms. It might slightly slow down how fast they heat up.

You can do your own thermal calculations for rooms using online tools, there are many, and Google will find them. If that radiator isn't powerful enough, you could change it for a larger (longer or taller) one, or a triple fin one, but they do stick out, and are ugly.

A radiator of the size you have should output about 2.4kW, which should heat a decent sized room, depending on glazing and outside wall insulation...

You can cheaply buy an infra red thermometer and use that to adjust radiator flow more accurately. Get all rads to the same temp top and bottom firstly, then adjust from there to your preference.

Something like https://smile.amazon.co.uk/Thermometer-Zanmax-Non-Contact-Temperature-Indication/dp/B07CJ1SJYX/ref=sr_1_4?ie=UTF8&qid=1543321340&sr=8-4&keywords=infrared+thermometer

ComicGeek

What temperature is the boiler set at, and what is the design temp for the heating system pipework? Very often see people turn down the boiler to 50/60 deg C to save money when the system is sized to operate at 70/80 deg C. Heat output from the rads is determined by flow rate and temperature difference, so you can easily halve the heat output from the rads by turning down the boiler temp.

BS design temps would be 18 deg C for bedrooms and 21 deg C for living rooms unless you've agreed differently with the installer.

moneyistooshorttomention

That had me heading into my boiler room to check what the boiler "said".

It says 47C.

I assumed the plumber I have in yearly sets the boiler at the correct temperature it's meant to be at - though I don't actually know. If it makes any difference - the boiler does both the central heating and hot water (for sinks).

Now wondering if the boiler got set at too low a temperature in the first place by the firm doing the installation - as I vaguely recall some "general comment" (not at me specifically) that was something along the lines of "Accidents older people can have from too hot water coming out of the taps". Wondering if I was being treated as in "older people category" - rather than in accordance with my own personal requirements (ie age irrelevant and too careful a person to "burn myself" on too hot water straight out of taps). Perhaps the original firm set it too low - to cater for this "generic older person" they had in mind - and not me?. Which then got followed by the plumber I now use just assuming it was set correctly - and leaving it at that....

He is from a different firm to the one that installed the boiler - as I don't wish to use them again.

Presume the size of the house makes a difference? It's 1,000 square feet in size - detached 2 bedroom bungalow, with cavity wall insulation and doubleglazing.

Re the temperature agreed with installer - they never said anything about that. The only time the temperature came up was when I complained that the kitchen was too cold and the wrong radiator must have been chosen. At that point - he told me that they had decided (without consulting me about it....) that they would choose a radiator appropriate to the kitchen being 18C. Not surprisingly - I felt cold - as I have all my house (apart from bedroom) set for 21-22 C. Hence they swopped the kitchen radiator and that one is okay. With only a small house like this - I basically treat it all as one large room - and that main bedroom iyswim.

Sounds like I'd better get out the booklet supplied with my boiler and see what they have to say about temperature the boiler should be - and if it matches the 47C the plumber I use for yearly maintenance, etc, has (presumably) set it at/kept it at.

bris

Sometimes 1 radiator, no matter what size just doesn't cut it. It may be best to add another. The room you describe sounds to me like it should have had 2.

Ectophile

To me, 47C at the boiler seems very low. I'm not surprised you're struggling to get enough heat.


The water going out of a condensing boiler should be perhaps 70C. this should give a return temperature of around 55C, which is ideal for the condensing bit to work.

moneyistooshorttomention

I've been trying to do a bit of reading re boiler temperatures after comments on here and references seemed to be to two different temperatures - one for the heating and one for the hot water.

That got me a bit confused - as I can only see one temperature on the front of the boiler and I'm wondering which one it is? I presume it must be the heating temperature?

So - I guess the figure I can see on front of the boiler should be 70C then? - and not 48C?

From this - I'm presuming what I need to do is get that plumber back again and tell him "The gauge says 48C. It should say 70C. Adjust it to do so". ???

I presume what would then happen (after adjusting the figure like that) would be that the boiler would kick in more often and "switch the radiators on" more often than it's currently doing?

moneyistooshorttomention

Just been out to boiler room and checked the boiler again.

The make is Vaillant Eco-Tec Pro 28.

The reading on the front of the boiler was 71 when I looked at it this time and then changed to 70 (as I looked at it). I could hire "firing up" during this.

So I presume the reading keeps changing then and that's how it's meant to be (dependant on whether the house thermostat has told it that it needs more heat or no at that point in time). What is the lowest figure that number should ever sink to??

Back to the drawing board on what the cause of the sitting room radiator not heating the room enough is then I presume. So - either an inadequate radiator or whether a 2nd radiator is needed as well.

Have measured the sitting room and it's approx 19' x 13' in size. The two windows are respectively large and rather darn large (those 1970s picture windows - doubleglazed by a subsequent owner).

I don't know how many btu the radiator is - it is a double-finned one. But reading about radiators I've done and it looks to me as if even radiators that are same size and same number of "fins" will churn out a different number of btu??? Hence my wondering if the radiator is a lower btu one and should be a higher btu one? Have I got that right - ie that even same size/same number of fins radiators could have a different btu output?

EDIT; I'm guessing there might be an element of "personal preferences" as to what people might want. So people used to the slightly colder temperatures where I now am might find this okay. But I'm from a warmer part of the country (average temperature 2-3 C higher than here and much less "wind chill factor") and like to be "actively warm" - rather than just "not freezing" iyswim. So they may not have adapted the set-up according to "customer has just said she's from Southern England".....and just done what the "generic customer in this area" wants iyswim.

DaftyDuck

There is variation between radiators of that size, but not much if it's modernish. What do the online room calculators say you need? That rad will be about 2.4kW. It should be roughly correct for that room size, depending on insulation and number of outside walls, etc.

Personally, I'd buy a thermometer and adjust the radiators accordingly. Then and only then I would wonder further. The thermometer is useful for finding cold spots on walls and windows, checking oven temp, bathwater temp, all sorts...

My guess is, the other rads are just getting a bit more flow than they require, starving that one. It's a simple cheap job if it's just that .... and no workmen need be involved!!!

Run a room calculator like https://www.bestheating.com/btu-calculator ... What does it say?

Oh... Just a thought.... you have de-aired the radiator....

Alex1983

The temperature on the digital display of the boiler just shows how hot the boiler currently is, you set the temperature by turning the knob to the right, 1 is the hot water temperature and the other is the radiator temperature.

moneyistooshorttomention

DaftyDuck wrote: »

There is variation between radiators of that size, but not much if it's modernish. What do the online room calculators say you need? That rad will be about 2.4kW. It should be roughly correct for that room size, depending on insulation and number of outside walls, etc.

Personally, I'd buy a thermometer and adjust the radiators accordingly. Then and only then I would wonder further. The thermometer is useful for finding cold spots on walls and windows, checking oven temp, bathwater temp, all sorts...

My guess is, the other rads are just getting a bit more flow than they require, starving that one. It's a simple cheap job if it's just that .... and no workmen need be involved!!!

Run a room calculator like https://www.bestheating.com/btu-calculator ... What does it say?

Oh... Just a thought.... you have de-aired the radiator....

Re "de-airing the radiator" - I do know that little thing. My father taught me about "bleeding radiators" back along. So I have checked that out.

I've wondered a bit whether other radiators could be taking a bit of the "oomph" the sitting room one should have so to say. So - if it's missing a bit of its "flow" - then is there a way I would be able to ascertain that and put it right myself? All I know to do is about bleeding radiators or changing the individual radiator thermostats up or down. I've also got the idea I should keep the hallway radiator set on medium (as that's the one right near the house thermostat and I gather that house thermostat might think the house as a whole is hotter than it is if I had the adjacent radiator on high).

So is there some "trick" or other I could manage to "adjust the flow" between the different radiators?

I was used to the "little man" I had in last house racing round the house twiddling with various radiators when he came in doing the annual service - but none of the workmen here seem to do that (though I'm paying rather more than I've been used to)....