Central Heating Problem

Duzzie

Hi all, it is the time of year to start thinking about putting the heating back on. Last night I put it on to test it, first time it has been on since may.

The boiler (gas) fired up fine and the downstairs rads heated up nicely but the upstairs rads stayed stone cold. I went around and bled all the rads and they were fine. I did a search on here and found a suggestion that it might be due to the expansion tank being empty. I went into the roof and there are 2 tanks up there, both the same size. I am assuming one is water, the other the expansion tank. Both had plenty of water in them, so it doesnt seem to be that or am I wrong in assuming the 2 tanks up there are water and expansion tank.

Any suggestions as to what else it could be, maybe I am doing (or not) something obvious.

The Muppet

Obvious question but did you check to see if someone had turned off the rad valves up stairs.

Duzzie

The Muppet wrote: »

Obvious question but did you chjeck to see if someone had turned off the rad valves up stairs.

I aint that daft, :D

I checked that, all bar one of them was on. Just had the one in the spare room off. I opened that valve for a while but no dice. I am sure it is probably something simple that I have done, or not done but that aint it. Thanks for the suggestion though.

JamesM

Duzzie wrote: »

I aint that daft, :D

I checked that, all bar one of them was on. Just had the one in the spare room off. I opened that valve for a while but no dice. I am sure it is probably something simple that I have done, or not done but that aint it. Thanks for the suggestion though.

Do you have a thermostat for the upstairs rads ?
Jim.

Duzzie

JamesM wrote: »

Do you have a thermostat for the upstairs rads ?
Jim.

No, there is the thermostat for the central heating downstairs and the thermostat for the hot water upstairs.

It was working fine last winter, over the summer we switched off the CH but did nothing else that i recall. The boiler continued to run for a couple of hours a day for the hot water.

JamesM

Both tanks in the attic are probably linked together and are the main water tanks. The heating system is probably sealed. Is there a pressure gauge on the heating system. And is it about 1 bar ?
Jim.

Duzzie

JamesM wrote: »

Both tanks in the attic are probably linked together and are the main water tanks. The heating system is probably sealed. Is there a pressure gauge on the heating system. And is it about 1 bar ?
Jim.

There is a guage on the boiler, is that the one?? I assumed this was something to do with the gas pressure. It is a Ferroli Tempra boiler, if that makes any difference. The gauge is currently reading 1/2 a bar.

JamesM

Duzzie wrote: »

There is a guage on the boiler, is that the one?? I assumed this was something to do with the gas pressure. It is a Ferroli Tempra boiler, if that makes any difference. The gauge is currently reading 1/2 a bar.

I'm not an expert on gas boilers, but the gauge is usually at about 1 bar. There is a valve somewhere, maybe in the hotpress, for filling the system.
You say that the upstairs rads are fine - there is water when you open the vents ?
Jim.

Duzzie

JamesM wrote: »

I'm not an expert on gas boilers, but the gauge is usually at about 1 bar. There is a valve somewhere, maybe in the hotpress, for filling the system.
You say that the upstairs rads are fine - there is water when you open the vents ?
Jim.

Yeahh, when I tried to bleed them, water came out. One had a wee bit of air but not a lot. Will check the hot press now

Duzzie

Ok, had a look in the hot press. There are 3 taps in there. One appears to be on the inlet into the hot water tank. The other 2 appear to be on pipes coming down from the loft, so presumably from the water tanks. All 3 taps were on. There are "splitter" systems in the hot press that I assume splits the hot water to each of the rads, one for inflow and one for the return. Two of these splitters have air valves. I opened these and there was no water or air coming from either.

Moanin

Turn off all the rads downstairs and open all the ones upstairs. Leave it for a half hour or so and reopen the downstairs ones and it should be ok?

Duzzie

Moanin wrote: »

Turn off all the rads downstairs and open all the ones upstairs. Leave it for a half hour or so and reopen the downstairs ones and it should be ok?

I'll give that a go later. Thanks. Just in case that doesnt work, please keep the suggestions coming.

Duzzie

Moanin wrote: »

Turn off all the rads downstairs and open all the ones upstairs. Leave it for a half hour or so and reopen the downstairs ones and it should be ok?

Nope, that didnt seem to work:mad:

Micky Dolenz

Have you ever had the ablity to turn off the heating upstairs before and just have heating downstairs? Do you have what looks like a valve with a box on it? from this box is a cable? maybe near boiler or in hotpress.

Duzzie

Micky Dolenz wrote: »

Have you ever had the ablity to turn off the heating upstairs before and just have heating downstairs? Do you have what looks like a valve with a box on it? from this box is a cable? maybe near boiler or in hotpress.

I do not know of a way of swithing off the heating upstairs other than the taps on the rads. The there are taps in the hot press as discribed in an earlier post. There is nothing that looks like a valve that I can see in either. I'm thinking that JamesM may be on the right track with the pressure within the system.

Micky Dolenz

MAybe, they should still work at 1/2 bar pressure, some of the rad would heat up.
Under your gas boiler you may notice a silver fexialbe type pipe, that is looped from one pipe to the next. There should be a black valve on it. turn the valve and the clock needle should rise. be sure not to overfill. stop at 1 bar.

Duzzie

Micky Dolenz wrote: »

MAybe, they should still work at 1/2 bar pressure, some of the rad would heat up.
Under your gas boiler you may notice a silver fexialbe type pipe, that is looped from one pipe to the next. There should be a black valve on it. turn the valve and the clock needle should rise. be sure not to overfill. stop at 1 bar.

Ok, I think we are getting there. There is no black valve or flexible silver pipe but.........

There is are 3 copper pipes coming out the bottom of the boiler, the gas supply, the inlet and the outlet. There is another copper pipe that connects the inlet and outlet about 6 inches below the boiler. On this connecting pipe is a red tap. This tap was open allowing hot water to flow between the inlet and outlet, effectively bypassing the system. I closed the tap and the upstairs rads imediately started heating up. The system pressure stayed at about 0.6 bar. I assume that this tap should be kept closed so that the hot water doesn't bypass the CH system?? The pressure didnt change with the tap closed. I have opened the tap again to see if the upstars rads go off again. Should I keep this tap closed??

Looks like my initial thoughts that I was doing something stupid were right.

copper12

That is a bypass leave it as it is if your heating was working before then it’s unlikely that this is your problem
Is your system a sealed system
An open system
A semi sealed system

Duzzie

copper12 wrote: »

That is a bypass leave it as it is if your heating was working before then it’s unlikely that this is your problem
Is your system a sealed system
An open system
A semi sealed system

Open I suspect but am unsure. There are 2 tanks in the roof but I have not decided what they are, one must be water, not sure about the other one.

The upstairs rads came on as soon as i closed the bypass tap. I cannot be sure that it was open when the CH was used before, it may have been "played" with over the summer. Should the bypass normally be open or closed??

copper12

This valve allows the minimum amount of water to flow thru the boiler when all zones are closed
If the upstairs came on when you closed this valve then most likely one of the kids turned it on full
So fire up the boiler with this valve closed see if all the heating comes on upstairs and downstairs .
If the rads heat up then you will have to adjust this valve again I had reply already typed so I might as well post it along with reply tales me that long to type I could not just delete it
Having had a look at some of your previous post the way you described your system is seems to be a Simi sealed system as the Ferroli Tempra boiler Is a system boiler so if you don’t have an automatic filling loop or a manual filling loop the it’s most likely fed from the attic
How old is the boiler and system can you see any motorised valves in the hot press or on top of the boiler most likely you have a thermostat turned down up stairs or one of the valves is stuck closed

Duzzie

I will play with the tap so that it is as open i can have it and still have the rads work. It was fully open.

The house is about 5 years old so the boiler is about that. There are 2 zone valves in with the boiler, one for the CH and one for the water heater. Both seem to be working fine. Had one go at my last place and had to replace it but these ones work fine.

Thanks everyone for your suggestions, we seem to have it sorted now.

copper12 wrote: »

This valve allows the minimum amount of water to flow thru the boiler when all zones are closed
If the upstairs came on when you closed this valve then most likely one of the kids turned it on full
So fire up the boiler with this valve closed see if all the heating comes on upstairs and downstairs .
If the rads heat up then you will have to adjust this valve again I had reply already typed so I might as well post it along with reply tales me that long to type I could not just delete it
Having had a look at some of your previous post the way you described your system is seems to be a Simi sealed system as the Ferroli Tempra boiler Is a system boiler so if you don’t have an automatic filling loop or a manual filling loop the it’s most likely fed from the attic
How old is the boiler and system can you see any motorised valves in the hot press or on top of the boiler most likely you have a thermostat turned down up stairs or one of the valves is stuck closed