Central Heating Troubleshooting Guide

Every now and then little things go wrong with your system, things that sometimes are simple enough to rectify by yourself.

Combination boiler - After each summer when your heating has not been on, you often get a build up of air within the system. When you switch your system back on this air will work it way back to the boiler and exit through the boilers automatic air vent, reducing the system pressure substantially. If this sends the system pressure on the boiler below around 0.5Bar the boiler will stop working. In this case you simply need to pressurise the system using the filling loop which should be located near the boiler. It is recommended you should recharge the system up to around 1-1.5Bar.

Radiators - Should one of your radiators not be working there are a few reasons; the radiator is cold at the bottom indicates there is thick sludge within the radiator, this would require cleaning out by a plumber; the top of the radiator is cold means there is air in the radiator and it requires venting, after venting always check the boiler pressure; the TRV is on number 5 but is the radiator is still cold, the TRV valve could be seized, if possible take the head off and give the valve a small tap with a hammer to try and jerk the valve back into place, should it be stuck solid it will need to be renewed.

Hot Water - Hot water can sometimes cause problems. If you have a combination boiler and when you run a bath the water is only ever just warm it is most probably down to the combinations hot water flow rate, smaller Kw combination boilers have a reduced hot water flow rate, around 8-10ltrs/min. Bath taps are conventionally sized to ¾” which means it is likely to have a higher flow rate than the boilers output. This means the boiler is letting more water than it can heat correctly through it, causing the water to be not warm enough. A simple fix is to only open the tap halfway or so, it’s cheaper than replacing your boiler!

When it comes to a boiler installation we always ask the customer which boiler they would prefer to be installed. This may be a Worcester, Glowworm, Vaillant or Baxi for example. We offer competitive rates on all boiler installs and central heating installs. Our boiler manufacturer of choice is Glowworm or Vaillant, we have no problems with any of their boilers, and they offer great performance. Both boilers come with good guarantees and we offer a good after sales service on them should you need it.

When choosing a boiler you can either use the information on our site or we can advise you on which system is right for you. We can tailor all of our quotes to suit a range of budgets.


Southern Counties
Heating & Plumbing

Copyright © 2015

Office Telephone: 02392 640883
Fax: 02392 361700
Email: lloyd.emery@sc-hp.co.uk

41 Brecon Avenue

Measures taken to ensure quality in our services:

  • Gas Safe registered No. 179300
  • Plumbing NVQ to Level 3 City and Guilds
  • ACS Gas Certificate completed
  • Green Energy qualifications
  • General Knowledge of Plumbing, Heating and Gas installations
  • Public Liability Insurance to £2million

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