Please find below a selection of good plumbing reference material, broken down and explained in a way that is easy to understand for the benefit of you, our customers, and the general public. If there is anything else you think we should show here, we would welcome your added contribution in order to help keep the information accurate and up-to-date.
There is a simple way to avoid the risk of falling victim to a ‘cowboy’ operator. Before you ask a technician to call, enquire if he or she is OFTEC Registered (and if not, why not?).
- They are individually trained at an OFTEC Approved Training Centre, and their skill independently assessed before they can apply for OFTEC Registration
- Have their work inspected from time to time by an OFTEC Inspector
- They are re-assessed every five years to maintain their Registration
- Carry an identity card confirming the type of oil heating work for which they are registered
- Have to hold appropriate insurance to work in your home
- They are able (in England and Wales) to self-certify work for which they are Registered. This saves you time and money, as non-Registered technicians must, by law, notify Local Authority Building Control, or submit plans when installing oil-fired appliances
- They will leave with you a written statement of the work they have done on your appliance, replacement parts fitted and recommendations for work needed in the future
A side effect is that this water, known as condensate, which is slightly acidic, has to be piped away to a drain or soak away.
The photo (below) shows a cutaway combination condensing boiler. It is mounted on a wall and the exhaust gases will rise through the plastic flue in the top left corner. Hot water is provided by a small storage tank on the right: the tank (which is covered by insulating foam) has been cut open to show the tightly wound quick refresh coil inside it. At the bottom of the photo are a number of pipes going into the boiler. One carries the gas for the burner and there are two (in and out) for the central heating system. The plastic pipe on the right carries the condensed water vapour produced by burning the gas. This water contains dissolved oxides of sulphur and nitrogen, making it slightly acidic.
We recommend seeking professional advice from an OFTEC registered installer before choosing an appropriate replacement boiler.
- An electronic timer or programmer that allows separate switching of heating and hot water
- A room thermostat
- Thermostatic radiator control valves (TRVs)
- Separate thermostatic control on the hot water system
The simple answer assumes that you are using the same source to heat water for the bath and the shower. This will be the case if you are using your central heating boiler or an immersion heater. But a lot of British homes have a “Power Shower” that uses electricity to provide a powerful and instant shower. Not only do they use water more quickly than a shower fed from a hot water system, they also use on-peak electricity that costs around 7p a unit, compared to 2p for gas. At this point it gets complicated, as to give a firm answer you would also need to know the efficiency of your heating boiler, the amount of insulation on the hot water tank and the losses on the pipework between the tank and your shower.
In fact, it may not make any difference either way, if you are using the central heating boiler to warm the water. For in most cases, especially in summer, we leave the boiler on for a fixed period of time, allowing it to heat up the tank of water. If the bath or shower is drawn off after the end of a water heating period, it will not affect the heating cost on the day it was used (for that has already happened) but on the next heating cycle. And if the tanks cools down then it will not be significantly affected by how much hot water was used after the previous cycle.
Of course, as with all the urban myths on this page, there are a few “ifs” and “buts”. If the tank is highly insulated (so standing losses are very low) and there is an effective thermostat on the tank, then the losses through leaving it on can be much reduced. And some people have a need for large quantities of hot water all day long, in which case they may have no alternative to leaving the immersion heater on. But in general, it is much better to install a timer – a heavy duty one, suitable for immersion heaters, should cost less than £20 and if you can fit it yourself safely, could pay for itself in a few months: an excellent energy efficiency investment.
Thermostatic Radiator Valves (TRVs) will only switch the flow to a single radiator on or off. They do not stop the boiler from firing (and so using energy). They are useful, but tend to be a rather crude control of temperature in a room, as they are affected by siting (please don’t put the sofa directly in front of them!) and are often not set at the right temperature.
In contrast a room thermostat is accurate to within a degree or so. What’s more, if it has been wired up correctly (in what may be called an “interlock”) it should send a signal back to the boiler to switch itself off if there is no demand for heating for either the heating or hot water circuits. This stops the boiler firing when the internal water temperature has slipped – ie. it stops so-called “dry cycling”, and definitely saves energy.
There are other advantages to modern room thermostats. They can contain an optimum start temperature sensor, which delays the boiler firing on relatively mild days, again saving energy. And if combined into full zone control, they can set different temperatures for different floors of a home – meaning that living rooms can be snug, without over-heating bedrooms.
One final warning: don’t put a TRV on a radiator close to the room thermostat, as the TRV’s operation will mislead the room stat.
Recently, a number of people have picked up on this, believing it to be a problem that only affects condensing boilers. They point out that in summer, when the boiler is only heating water, it operates at part load and does not normally enter condensing mode. “Aha!” they say, “in that case it must be wrong to use a condensing boiler only for water heating.” Actually, that’s not true. They are right to point out that the boiler may not be in condensing mode, but even so the larger (or second) heat exchanger unit in a condensing boiler still means that it will operate at a higher efficiency than a conventional boiler (unless it has a very high internal thermal mass). So a condensing boiler is still likely to be cheaper to run than a conventional one in summer. The Government’s A-G boiler energy rating (SEDBUK) is based on average seasonal efficiencies, and takes into account the lesser performance of boilers in summer, so an “A” rated boiler will use less fuel over the year than a “B” rated one, and so on…
So the salesmen have moved on to another product – the magnetic ring that aligns the gas molecules and achieves amazing improvements in boiler efficiency. Well, I would be amazed if these worked as well as they are claimed to, as in some cases they would end up giving boilers more than 100% efficiency. Preliminary investigations by Government scientists suggest the claims are just hot air – I expect that by the time we know for certain, the salesmen will be selling us something else again…
On the other hand, there is evidence that strap-on devices designed to stop scale forming in hot water pipes may be effective in hard water areas. These apparently work by precipitating out limescale into microscopic particles that stay suspended in the hot water, rather than coalescing as scale on the walls of the pipe. It’s not clear how much energy they can save (and it’s unlikely to be anywhere near 10%), but hopefully there will be independent test results available in the near future.
- There is no legal requirement in the United Kingdom to obtain a landlord safety certificate for oil fired equipment installed within a let property.
- However, BS 5410 Part 1 requires oil fired appliances to be serviced periodically in accordance with the manufactures instructions.
- Oil tanks and oil feed pipe work should be checked for general condition and any leaks repaired. This is to reduce pollution incidents which may result from inadequately stored oil.
- To promote safety of tenants and instill peace of mind to Tenants, Letting Agents, Landlords and to satisfy some property insurers, it is recommended that an OFTEC Registered Technician services and inspects an oil installation at least annually.
- As well as peace of mind, planned maintenance can keep an appliance operating at peak performance, reducing fuel bills, save on costly call out fees, if an appliance fails and reduces the risk of carbon monoxide poisoning.
OFTEC Registered Service and Commissioning Technicians are the only persons that can obtain industry recognised OFTEC CD/11 Service and Commissioning Forms. The form provides written evidence of service/maintenance confirming the condition of the appliance and installation, any non conformities and any remedial work required to bring the installation up to current regulations standards. The Landlord/Letting Agent should retain a copy of the CD/11 form so they can demonstrate that they have met their legal duty of care to the tenant by having the installed oil fired equipment properly maintained and tested.