Be Your Own Surveyor, Plumbing and Heating

Be Your Own Surveyor, Plumbing and Heating

I wrote about solid floors last week, this week it’s plumbing and heating.

As of April 2009 all new boilers fitted need to be of the condensing type. They are more fuel efficient as they use a heat exchanger to extract heat from the flue gasses before they leave the house. They are recognisable by having not one but two small-diameter pipes (usually 15mm) exiting the house. One is an overflow pipe which all boilers should have and is usually copper. The other is a condensate pipe, which is usually plastic and should discharge into a waste pipe or soakaway as the water can be slightly acidic. The overflow should be bent back to face the wall to prevent sudden ejaculations hitting anyone.

Overflow pipe above condensate pipe below

The disadvantage with condensing boilers is they are far more complicated hence more to go wrong. I wouldn’t be too concerned about a better make like Worcester or Vaillant but cheaper ones already have a bad reputation for breakdowns. Pre-condensing boilers are more reliable but any boiler over about ten years old may start to give problems. Old back-boilers are very inefficient and definitely need replacing!

Modern houses usually use plastic pipe which is very reliable if jointed correctly (never allow a labourer to do it!). It should be protected from extreme heat and direct sunlight.

1980s houses often used micro-bore copper pipes of about 8mm diameter. The advantage was they can be easily bent without a pipe bender and are much easier to install. Unfortunately like a lot of short-cuts they are also unreliable.  Joint leaks are common as is corrosion due to thinner metal. The fittings can also be hard to source. If they cause problems it’s usually best to replace the lot. Many bad ideas were tried out in the ‘80s and that’s given modern houses an unjustifiably bad name in my opinion.

Earlier properties from about the mid 20th century used 15mm or 5/8” copper. Before that they used galvanised steel, iron or lead. Pipes this old almost certainly need replacing, and lead drinking water pipes needs replacing anyway for health reasons.

One little tip to see if a DIY plumber has been at work is to check the taps on all basins, baths and sinks. Cold taps should always be on the right. A cold tap on the left indicates DIY plumbing, but even a DIY plumber has a 50% chance of getting it right.

Next week I’ll cover wiring and electrics.

All the best,



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