Help with thermostats?

angela110660

I have watched all the progs and found interesting. I wonder though if anyone can advise me about the heating system and also the fridge thermostats.
When they say turn down by 1 degree - how does this equate to radiator thermostats, hot water cylinder thermostat and what do the numbers inside the fridge relate to? I have never known this information and none of the instruction leaflets give you a comparison thing like you get with gas to electric ovens etc. By the way we have never had a wall thermostat since the heating was installed as the fitter said that the radiator things worked per room - which they do.
Advice gratefully received.

Pink.

Hi angela,

I have moved your post over to the In My Home board, where hopefully you will get more replies.

Pink

bunking_off

angela110660 wrote:

When they say turn down by 1 degree - how does this equate to radiator thermostats, hot water cylinder thermostat and what do the numbers inside the fridge relate to? I have never known this information and none of the instruction leaflets give you a comparison thing like you get with gas to electric ovens etc. By the way we have never had a wall thermostat since the heating was installed as the fitter said that the radiator things worked per room - which they do.
Advice gratefully received.

I don't think things are quite so scientific as there being a direct linkage to temperature.

For the fridge/freezer, suggest getting a thermometer. My fridge has a digital readout, and for ref the fridge works at 4 degrees, freezer minus 19 degrees. Certainly for the fridge, it'll let you adjust anything from 2 to 6.

Your central heating is a bit of a weird system - perhaps ask the question on the DIY board. It is true that if all the radiator 'stats choke the system off it's defacto doing the same as a central room thermostat, but I would have thought there's a bit of a nuance in that with a room thermostat when it triggers off the central heating pump is switched off, whereas if you simply rely on radiator 'stats the pump will merrily push the radiator water around a circuit bypassing all of the radiators. However, I'm no plumber so I'm probably completely wrong on that. I live in a new build, and we have a central thermostat in the hall, then thermostats on every radiator : would have thought if the builders could cut costs by omitting the central thermostat, they would have...

paul_h

Some installers do prefer the no room stat method on modern combi boiler installations and it does work fine until a valve fails... modern systems can be fitted with pumps which reduce output (pumps with 'integrated pressure differential control') as the radiator valves close, avoiding pressure rise in the system.

Hmmm... I still prefer a system with a central room stat.

Not sure about fridges/freezers, but on radiator thermostatic valves, 1 division is equivalent to 3 degrees C. Most cylinder stats are marked with the temperatures, in 5 or 10 degree steps.

angela110660

Thank you for replies so far. Will have to get a thermometer as suggested. You would think though that even if they have to use different systems for the items I have suggested, that they could at least give you the base temperature from which you can then work out the numbers? For example, as Paul H says that the cylinder stat goes in 5 or 10 degrees - is that from 0 degrees or from 20 or what?
Sorry I am dense.

moneysavingplumber

All systems should have a room thermostat. If they do not, the boiler will 'cycle' all the time the central heating is on. Energy efficiency guidelines under Part L building regulation dictate the minimum control on central heating systems should be a programmer, room thermostat, cylinder thermostat (if not on a combi) and TRVs on all rads except the one closest to room stat. The system should have an automatic bypass, and larger systems should be 'zoned' with separate stats for different parts of the property.

Your cylinder thermostat should be set to 60 degrees C. Any less than this will help proliferate limescale and bacteria.

moneysavingplumber

bunking_off wrote:

I live in a new build, and we have a central thermostat in the hall, then thermostats on every radiator : would have thought if the builders could cut costs by omitting the central thermostat, they would have...

Yes, builders (and alot of plumbers) have been doing this for years, and it's wrong. At last they have been given guidance under building regs that both room stat and TRVs are necessary.

angela110660

[QUOTE=

Your cylinder thermostat should be set to 60 degrees C. Any less than this will help proliferate limescale and bacteria.[/QUOTE]
Thank you for your interest and advice. Which number would be 60 degrees? We usually have the cylinder thermostat at 3 and the water is piping hot - is that right? We live in a hard water area by the way so limescale is a problem for us.

moneysavingplumber

What make is the stat? It will depend on the calibration, and a quick call to the manufacturer's technical department should tell you. It shouldn't be hot enough to make tea with, as this may cause cavitation and problems with certain thermostatic appliances. Get a thermometer and test the temperature you're getting at the tap if you can't get decent info on the stat.