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Combi Boiler Problems

Combi or Combination boilers can be quite useful and can serve the purpose of space heating as well as provide domestic hot water (DHW). These are more commonly known and used in the United Kingdom and other European countries. They do not provide instant hot water however; fire up once there is a demand for water. This can take sometimes up to a minute for the user to actually have hot water at the tap. They are considered inconvenient and an environmental waste of water by many. They have their shares of drawbacks as well, such as low water pressure during peak times. Users find issues and questions concerning these systems and turning to an Expert to help will assist with the frustration faced.

To get information about other Combi Boiler questions and problems, listed below are common questions answered by Experts.

Combi Boiler Should the Combi Boiler be turned off as the pipes are frozen until water supply resumes?

Essentially a Combi Boiler is a sealed system filled with water and once filled it may not have the need for fresh water to be added. This is unless the Combi Boiler was being serviced or if the boiler has developed a leak. In such a situation of frozen pipes, the pressure of the Combi Boiler should be determined. If the pressure is above 12 PSI and below 25 PSI, then it should be fine to remain on. When the Combi Boiler is turned off, the pressure should be between 10 PSI to 15 PSI. If the reading is 0, it could be an indication of no water pressure and the possibility of damage to the Combi Boiler. In such a case, there is usually a self-fill valve available which can be manually opened to allow water inside. In case this pipe is not frozen, it can be opened to allow water to enter and fill the system up to 12 PSI after which it can be closed. If it is not possible to fill the system, it is better to leave it turned off until at least 10 PSI of water is filled to prevent damage.

What could be causing a problem with the hot water flow on the Combi Boiler? Will installing a 1.5 bar pump in the kitchen to feed the 15 mm pipes of the bathroom help?

In this scenario, installation of a recirculation system would be more beneficial rather than a pump. The reason this problem is occurring is that the piping lengths are at a distance from the water heater. A similar system (can be attached and piped to accommodate the setup using the basic principles. In case a pump is installed in the current setup, a separate return line from the existing lines would need to be piped from the furthest point of hot water or faucet from the heater. It needs to return to the heater with check valves and “T'” back into the cold feed to the tank. Additionally a pressure expansion tank is recommended in the system to avoid excess buildup of pressure thereby dumping the pressure relief valve.

How can the pilot light of the Worcester Bosch combi light be re-lit?

Typically majority of the Combi Boiler units have the electronic spark ignition feature and light automatically when there is a demand for heat. In case they fail to light, it could be due to a variety of reasons. In that case, you would need to listen to the boiler operation intently when it is first started. A fan can be heard and then one should listen for clicks over the next 60 seconds or so. This can help gain a lot of insight on what could be causing the problem with the pilot light.

On a Vaillant Eco Combi Boiler, where should the water supply be turned off so that the kitchen sink can be dismantled?

Normally shut off valves are present under the kitchen sink or are in the basement after the Combi Boiler. If these valves are absent, the water can be shut off at the point where the water enters the house. If the cold water supply to the house is turned off, it will shut off the water supply to the Combi Boiler as well. Alternatively the Boiler usually has an electrical shut off switch at the boiler. This will shut the boiler down and prevent it from firing while working on the faucet. Once the work on the faucets is complete, the electrical switch of the boiler can be turned on. It would be a good idea to consider installing new stop valves under the kitchen sink to avoid switching the boiler off.

Combi Boilers when installed are one of the main and important components in a heating system or installation. Any issues faced with them need to be interpreted and then examined carefully as you are dealing with a source of heat and pressure. Sometimes, the repair work elsewhere can affect the operation. It can be difficult for an inexperienced person to deal with the issues on their own without guidance and instructions. Hence to get a fair idea regarding Combi Boiler problems, Experts opinions, information and perspective will prove useful.
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