Central heating never hitting it's temperature

Pulsedriver

Pulsedriver

Pulsedriver

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Hey folks,

In our house we have a Vailant Ecomax 828/2e combi boiler, and have recently had a Hive thermostat fitted.

What we have noticed is the heating never hits the target temperature, in this instance, set to 19 degrees, admittedly it is only on for a couple of hours in the morning, but it's the afternoon where I am concerned.

For example;

Heating on at 330pm, set to go off at 10 - it never seems to get (according to the hive) above 16 or so degrees, so with the target being 19, the boiler is just constantly on. Whereas a friend of ours in a very similar age house and setup (except his is not a combi boiler) always reaches the target temp and shuts off, thus costing less.
The loft insulation is all done to the new standard, so I can't see what else could cause it? Perhaps the radiators not pumping out enough heat?
 
Do all the radiators actually feel hot? Does the house feel like it has warmed up or is it still "cold"?

I don't have a hive unit but our thermostat is in the hall and can get from 14c-19c+ in about 30-45mins or so.
 
First question is, after 6.5 hours of heating in the afternoon/evening, does the house feel warm? Do the radiators get hot? What is the boiler temperature dial set to?

Chances are the boiler is not constantly running. It is probably turning on, reaching max temp, then shutting down, before repeating. This most likely means the rads are not getting sufficiently hot. Provide some more info on what exactly is happening.
 
Lack of info is annoying! Recently had a Hive fitted so are we to assume that this issue is new and therefore related to the Hive? Or did this issue exist before/could it have existed before?
 
Is there decent water pressure in the boiler? 1.6 bar I think?

Are all the radiators getting hot? At the top and at the bottom evenly? If not you have air in the system and need to bleed your radiators. If it keeps happening or you lose pressure you have a leak somewhere.
 
The room thermostat only turns the boiler off when the temperature has reached its target, it does not set the temperature of the radiators, so look at your boiler and see if the heat the boiler kicks out is set high or low, if it is low then the house is going to struggle based on the radiator size you have..

The only way to heat the house with a low flow temp is to have oversized radiators..

Which is the case regarding Air Source Heat Pumps.
 
Hey guys sorry for late reply, firstly the hive is amazing so definitely whoever thought it may be that, don't worry! It's brilliant
I didn't have a thermostat before having the hive fitted.
Interestingly I turned the boiler temp dial to maximum (was on 70) now on 82. That appears to have made a difference, I accidentally changed to 17 on the hive earlier and the heating was off as it hit that temp earlier. I've now put to 19 so we shall see if it gets there. Will keep updated and check rads
 
Pulsedriver said:
Hey guys sorry for late reply, firstly the hive is amazing so definitely whoever thought it may be that, don't worry! It's brilliant
I didn't have a thermostat before having the hive fitted.
Interestingly I turned the boiler temp dial to maximum (was on 70) now on 82. That appears to have made a difference, I accidentally changed to 17 on the hive earlier and the heating was off as it hit that temp earlier. I've now put to 19 so we shall see if it gets there. Will keep updated and check rads
Click to expand...

So the temp is in Fahrenheit on the boiler but Celsius on the gauge?
 
boiler stat and room stat will both be Celsius

it wont be hitting the temp because his rads obviously aren't an adequate size for the rooms
 
Turning water temp up Should make a big difference. However if the house is badly insulated you will struggle in the today's temperature.
 
because his rads are getting red hot and the room stat isn't hitting target temp

all these armchair boiler experts going check the pressure etc etc doesn't help things
 
Check the boiler to see if its been range rated - this is done in the settings and lowers the kw output of the boiler to save gas.

Just google vaillant range rating to find out more but it should be in the installer manual

Its actually better to have it on constant but low(when needed) as this helps the boiler go in to condense mode more and will save on gas
 
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When I got a new boiler, the rads got red hot, before that they felt hot, but you could leave your hand on them for ages. They didn't really radiate any heat out.

Now, you can't touch them for more than half a second. I have hive and it works perfectly, mostly.
 
He didnt say red hot but he did say the boiler was set to 70c which is red hot, most people have showers at around 45c.. 50c max, 70c is red hot..

that doesn't mean the rads are getting to 70c though, if they are they're all too small as the house isnt reaching the target temp, if they aren't their could be a massive build up of iron oxides, dodgy pump etc..
 
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