Radiators not hot

[chillygirl]

Hiya,

I was wondering if someone could help me please. I brought a newly refurbished house in July this year, which has had a new boiler and all new radiators fitted. The hot water has always worked perfectly and I've only recently tried the central heating.

The problem is that the radiators upstairs don't get properly hot. They get warm at the bottom, but are still ice cold at the top. I have tried bleeding them, but no air comes out.

They are all turned up as high as they will go and so is the thermostat.

I don't know what else to do. Do I need a plumber? or is it something I can DIY?

The boiler is a Valiant - I'll have to check the exact model when I get home.

 

[JohnD]

Is there a feed and expansion tank in the loft, or is there a filling loop at the boiler?

When you bleed the rads, does water squirt out forcefully? What colour is it?

When you turn off the downstairs rads, do the upsairs ones get hot?

Have some of your rads got thermostatic valves?

Have you found the circulating pump? What speed is it set to?

 

[hi-spec plumbing heating]

shut the upstairs rads till downstairs fully hot then open the upstairs one turn

sounds like the whole system needs balancing

 

[chillygirl]

Is there a feed and expansion tank in the loft, or is there a filling loop at the boiler?

I don't think there is anything in the loft - but I haven't checked. It's a combi boiler, so I didn't think there would be a tank as well

When you bleed the rads, does water squirt out forcefully? What colour is it?

No water comes out at all - no air comes out - nothing happens (and, yes I am doing it right!)

When you turn off the downstairs rads, do the upsairs ones get hot?

I'll try that tonight

Have some of your rads got thermostatic valves?

Yes, they all have them - I have turned them all up full

Have you found the circulating pump? What speed is it set to?

No idea what a circulating pump is or where it would be!?!?!?! (sorry!)

Thanks for the replies - should I call a plumber??

 

[JohnD]

"When you bleed the rads, does water squirt out forcefully? What colour is it?"
"No water comes out at all - no air comes out - nothing happens (and, yes I am doing it right!)"

your system needs topping up. I am surprised it works at all.

If you have the instructions, find the filing loop and the pressure guage and work from that.

If not, someone who knows your make and model of boiler should be able to explain.

Topping up is a Householder job, but if there are other faults, start asking round friends and neighbours for someone they recommend who does Central Heating repairs. You might find the name and number of the person who installed it is on a card or sticker on your boiler.

BTW, you are more likely to need a CH or Boiler engineer than a plumber; not all plumbers will be good at boilers.

p.s. A circulating pump looks like this, but I don't think that's the problem. I think the problem is that you have lost water and/or pressure

 

[chillygirl]

Brilliant - thanks for your help

I'll have a look at the instruction manual tonight and see if I can work out how to top it up. Otherwise I do have a card of the firm that installed it - so I'll call them. Are they likely to be cowboys though as it's not working correctly and is a brand new system??

Sorry - I didn't mean to offend any plumbers and/or CH engineers!!

 

[JohnD]

it may have a leak. You will find out by seeing how long it stays full and pressurised after topping up. If, when you bleed rads, you get black water out, then it has some corrosion inside and ought to be cleaned and inhibited (this should have been done at installation)

As they installed a new boiler they ought to be CORGI or similar members. If not then they probably are cowboys as they are not allowed to instal boilers for pay otherwise.

I am sure many of the professionals on here will tell you that they take a pride in their work and would fix a fault arising less than 6 months after installation for free.

I am just a householder.

 

[gas4you]

Could just be the air hascome out of the system and needs topping up with nothing wrong at all.

Depending what Vaillant it is you will either have a 1, 2 or 3 year warranty and hopefully at least 12 months on the pipe work etc.

Vaillants have 2 grey plastic knobs under the boiler (fixed to the base). Turn one then the other , they only turn 90D and watch the pressure gauge rise. When it gets to about 10 o'clock position turn off valves underneath. Bleed the rads until water comes out, then re-pressurise system.

Press the - button and this should read about 1.2- 1.4 on the digital display.

As the system seems empty, turn off the boiler at the on/off next to the pressure gauge and then press the + button whilst turning boiler back on.

Hold the + button until P0 appears in the display then let go and press the + button.

Boiler will self purge to get rid of air in it.

When the display reads about 23 or so it has finished and it is ready for use.

You then need to check the rads for air again and check if you need to top up the pressure again.

 

[chillygirl]

Hello,

Firstly - thank you all so much for your replies

Secondly - I was getting mixed up with my boiler (I had Valiant at my old house) having checked last night this boiler is actually an Ideal Excel HE C32. Sorry!

I looked at the papers I have for it last night and telephoned the man that installed it (he is CORGI reg). He wasn't really that interested in my problem and went on to say that if he comes back to look at it he'll make a charge, as he doesn't work for free! I didn't expect him to work for free, but he could have been more polite! He got very defensive. He asked me to call him again today to see if he has time to come and have a look.

I also read through the manual last night and checked the pressure on the boiler - it's down to about 0.2 which I guess isn't good, but the instructions don't say how to re-pressurise. They say to seek help from a "competent person".

Is the low pressure the reason for the rads not heating up?
Does anyone know if I can re-pressurise it myself? and if so, how?
Is it dangerous to carry on using the heating and hot water when the pressure is so low??

Thank you again for all your help.

 

[bobthebender]

Your boiler needs a pressure of 1.5bar.
As you look at the boiler there should be a filling loop that joins the second pipe from the right to the last pipe.(cold mains to ch return)
You may see a fitting on both that the filling loop screws to or the loop may be there ?
Use the tap on the cold feed to top up the system and bleed rads.

 

[chillygirl]

Your boiler needs a pressure of 1.5bar.
As you look at the boiler there should be a filling loop that joins the second pipe from the right to the last pipe.(cold mains to ch return)
You may see a fitting on both that the filling loop screws to or the loop may be there ?
Use the tap on the cold feed to top up the system and bleed rads.

Brilliant - thank you.

I'll have a look as soon as I get back home.

They seem to have boxed in some of the pipes at the bottom of the boiler - so I'll have to take all that down I imagine

 

[JohnD]

this is good too
http://www.diynot.com/forums/viewtopic.php?p=245122#245122

 

[chillygirl]

Woo hoo!!!!!!!!!!!!!!!!!!!

Thank you all so much for your help! I've done it - re-pressurised the boiler, the bled the rads and then re-pressurised the boiler again and my house is now roasting!!!

This is a great website and I'm so pleased that you've all helped me save some money!! Thank you.

C

 

[gas4you]

If the installer came round to help no doubt he would have got recommended by you.

Now obviuosly he won't

This is why I always go back to any of my installations to help the customer and always (nearly) with a smile on my face and make a joke of it if it is something simple as this

I wouldn't charge either, but then I am expensive in the first place