An Old Boiler

[lifeson]

The advantages of a combi include instant high pressure (depending on the size of the heat-exchanger) hot water delivery and the elimination of space wasting HW cylinders and header tanks.

A little knowledge is a dangerous thing
One of the most important factors to consider with a combi boiler is the location i.e how far it is from the boiler to the main draw off point
The market is moving away from combis and legislation may be introduced soon which will make it harder to recommend a combi.
By far the most importnat consideration when choosing a boiler is not the heating but how you use your hot water. Do you shower or bath, how many people in the house, lifestyle etc.

I used to sell central heating for the largest installers

Part L building regulations (England) mean you will have to have a condenisng boiler (unless there are exceptional circumstances)

 

[Over The Hill]

I bought one from Worcester Bosch direct, much less than via the plumber.

My one was oil so I had less options. Lots of rules now apply so you needto get it fitted and a certificate issued (= no cash deals) and keep all the stuff for ten years for if you sell your house.

Get a few local recommendations and get a few quotes.

I did all the plumbing to fit it and wired it all in but then got the boiler man (well boiler woman actually (cue old porno film)) to commision it and sign it off. Tons of regs on outlet place and venting etc etc.

 

[Night Train]

Combi or tanked hot water really depends on how you use hot water, how much of it you use, when you use it and if you use it all in one lump or in dribs and drabs through out the day. Also if you are intending to add solar hot water then a tank is a necessity.

Due to the size of my house I installed two Vailant combi water heaters with a capacity of 98,000 btu each and 11 litres per minute of hot water at 60C. They were on special offer and so I bought two of them about 12 years ago. They have been working fine all this time with just a diverter valve change around 5 years ago. The instant hot water works fine with my hot water usage which is infrequent small amounts and local to each boiler.

With hindsight I think I would have put in a single condenser with a bank of hot water cylinders with solar heating with a pumped hot water mains around the house. It would make best use of the 10 square metres of south facing roof slope. The storage tanks would store all the solar heat switching from tank to tank as each reached its storage capacity and was topped up from the water heater. Excess heat would be used to suppliment the space heating and I would have installed under floor in stead of radiators to use the lower temperature water. Everything would be super insulated to reduce losses.

 

[mickle]

A little knowledge is a dangerous thing

Ooooh handbags!

 

[Aperitif]

Spare a thought for the good old Megaflo - if we are talking about 'cold water tankless' systems. These give balanced high pressure output and come pre-plumbed etc etc... In fact Crock - rip the lot out and start afresh...you know it makes sense!