Our radiators in our new home never seem to get hot! The system uses a potterton boiler (not combi) about 4 years old. In my old house the radiators got so hot that you couldnt keep your hand on them. In our new house the radiators never get that hot even after coming on for about 2 hours. The thermostat is up full there is a temperature dial built into the boiler which is up full, all the radiators have been bled. Does anyone have any other ideas or advice???

Cheers

Is the boiler the correct size / power for the amount of radiators in your house?

The Boiler has a thermostat too!! (inside)

Pete

Even though you have bled the radiators, there could still be air in the system depending on how often you bled it.

I would check the thermostat on the boiler, then check that the boiler is suited to the number of radiators you have installed.

Pete, above and beyond this?
there is a temperature dial built into the boiler which is up full,

If so, do you know where?
Ta,
Nick.

The system was installed in the house when it was built about 4 years ago, we moved into this house about 5 months ago. How would I know if the boiler was the right size? and Where is ths mysterious Boiler thermostat?

Cheers

The model of the boiler may help to find its rating, and also indicate where the thermostat is.

If the thermostat is on full, then it could be faulty, and need replacing.

Do you have those thermostatic rad valves? I've known them to stick before now.

dnb is right
some makes of rad thermostats do stick .The reason is that the heating is off all summer and the rubber seat sticks to the inside of the valve.The symptoms are that the rad is stone cold.
it sounds like a system fault(installation) if the rads take that long to warm up.Try finding your pump and see what speed its on.if its on 1 try it on 2 and see if the water is circulating faster.
either that or they have connected the pipes the wrong way round on the boiler:eek:

Duncan

The rads do get warm evetually but the CH system needs to be on for about 3 hours first :eek:

I will take some pics of the boiler and thermostat tonight to see if anyone recognises it - who needs nubiles on P1's eh! :D

Cheers

Alright Russ, first things first mate, has the rads always taken so long to heat?? If no, then there's nothin wrong with boiler/system size.

After readin the other threads, if it were goin to be the t.stats on the rads getting stuck then more than likely the rad wouldn't heat at all,it'd be cold all over.

Are the rads heating like goalposts? Up the sides and along the top?? If so then the problem is sludge, BUT with the system only bein 4 years I would rule that one out, but only you can tell.

Now, here's my theory...I presume that you are able to have your hot water & central heating on seperately?

If so, you should have 2 zone valves (Small silver boxes) poss near the cylinder somewhere, could honestly be anywhere but try near the pump/cyl etc first.

The way that I see it, it's as if the CH (Central Heating :rolleyes::D) zone valve isn't opening as far as it should therefore restricting the flow of water to the rads. This would then in turn off the boiler,at the stat, because it thinks that all the rads are satisfied in turn taking a lifetime to heat,or give what your getting.

Have a wee peek for this valve and let me know how you get on mate.

Oh just keep your fire on for the meantime!! ;)

Hope this makes sense....

- Bee

The Thermostats are normally ON the pipework which takes the water TO/FROM the boiler (inside the casing) - on yours it will probably only have an 'Overheat' thermostat, IT could be clicking in too early and not allowing the full temp to be reached.

Chairk - the above thermostat is IN ADDITION to the consumer operated thermostat - it wouldnt be wise to play with it unless you know what you are doing, its just an item that may have become faulty and they are cheap too!!

Sludge in the system is another possibility - but as the system is only 4 years old I cannot see that this is an issue.

Pete

Just a daft question - but have you checked the speed of the CH pump ?

I had to swap my CH pump recently and the buggered one ran on top speed (b4 it packed up), when I put a direct replacement (and I mean really the same b4 anyone comments) in I only have to run it on 2/3 speed and I get the same heat as b4.

Put the speed up to 3/3 and it makes the rads hotter.

T.

Some great advice here chaps, I forgot to take a piccy of the multitude of valves next to the HW tank last nite but rest assured I will (I aint got a clue hot to speed up the pump :rolleyes: ) Incidentally the system is a potterton Suprima 30. I will be back later with pics.

Thanks again.

How many rads have you got, type of house etc as a Suprima 30 isn't going to be capable of heating much when you consider an average semi-detached house will probably need a Suprima 60 for example...

Mog

Russ mate,

You need to make sure the pump is on a fairly slow speed and feel the flow pipe coming out of the boiler,shut a few of the rads off as well(how many rads r on the system)is this pipe getting hot and does the burner shut down when the pipe becomes hot or is the burner constantly running,remember though its probably a cast heat exchanger and will take up to 30 mins to get some heat in it.You may have a problem with the burner unit or a dodgy boiler stat.

UPDATE - after snooping near the HW tank I found a dial with 1-2-3 settings, I changed the setting from 1 to 3 and I heard a faster flow of water et voila HOT RADS! I am assuming the dial is the CH pump.

I also think that the system is not powerful enough for the house. We have a medium sized 3 double-bedroom detached house yet the system is the Suprima 30! The rads however are too small for the rooms ! hey ho

Anyways does anyone know if I will have any probs leaving the setting on Number 3 (max) setting?

Thanks all again for some great advice!

[Edited by Ru$$Rip - 12/14/2002 4:47:44 PM]

Hi as per my reply above ....on average your size house will probably need something like a Suprima 70/80 and the rads sizing according to room requirements.

Mog

Russ,

I would put the pump on no 2 as leaving on 3 may cause water to flow out the vent pipe obove the tank which is not ideal as it will be drawing water out the cold feed as well.