Nickthegas

What are the disadvantages of installing a combi boiler?

Main disadvantage with a combi boiler is low water pressure and waiting time to fill a bath and or multiple users trying to use hot water at the same time. Also scaling of the secondary heat exchanger within the boiler if you live in a hard water area. The other thing is no combi runs the central heating and hot water at the same time so if someone is running a bath then the central heating would be off. Most combis only have a 15mm hot water output and a 15mm cold water input which restricts the amount of water passing through the boiler so restricts its usage

What size boiler do I need? How to choose?

Carry out heat loss calculations for the building This will tell you the KW heat loss. Add 10% for pipework. Find out your cylinders coils output and add this to that figure. This will tell you the size of boiler required for your property. If you live in an exposed area then you will require a bigger boiler same as if you don't have any insulation or double glazing If its a combi then the same calculation is used but ignore the hot water element. Carry out water flow test at main tap this will tell you what the maximum expected flow rate you can expect at the hot tap. However if anyone flushes the loo or another tap is opened then the rate will drop. So if you have multiple outlets then a combi would not be suitable, also of you have a combi, shower valves may need to be changed and even high pressure toilet valves may need changing also. So look for the hot water output for that boiler and that is what would be required.

In what order is a bathroom installed?

Strip out old bathroom including tiles. Complete any building works including any damp or rot, ensuring floor is sound and structurally safe. Install new pipework and drainage to the required plan. Install waterproofing or moisture resistant material if required. Complete any electrical works to plan ensuring if any zone one work is required that it has an RCD fitted and materials conform to current regulations. Carry out any electrical tests that are required. Fit bath and or shower tray if required. Fit any radiators or towel radiators that are required and ensure they are working correctly including any inhibitor that may have been lost due to removal and or drain down. If sludge has been found then advise customer. Carry out dry run of any other sanitary ware to ensure fitment and drainage falls. Test bath and or shower for falls and correct operation and to remove debris from pipework and valves. Carry out floor tiling then wall tiling from plan ensuring levels and appearance are correct. Fit sanitary ware to plan. Fill bath and silicone in place leaving the water in bath for 24 hours. Check for any leaks. Silicone shower and rest of bathroom including floor area. Fit any storage required. Second fix electrical and test certificates are filled in for minor works. Finally clean everything and hoover through to remove remaining dust. Carry out final check and carry out hand over to client explaining everything on how it works and any guarantees that may need to be filled in.