please help with system design

[hamel0178]

Hi all, I am new to these forum's, so not totally sure how they work. Anyway I've been a service engineer for about 6 months and done a few boiler replacements in that time.

I have just been offered my biggest job so far. The property has no CH at the moment and is a 3 bed flat with 3 bathrooms. Two of the bedrooms and bathrooms are in a loft extention. I'm thinking to install a system boiler with an unvented cylinder, but just wondered if anyone has any better ideas. Not sure if this idea would work if all showers were being used at the same time.

I'm not qualified to do the unvented part, so will be calling in someone else for that part if required, but also wanted to know if the unvented cylinder requires a secondary pump?

Any help would be much appreciated.

Cheers, Hamel

 

[Tibbot]

Not doubting your ability to do the job, but the best advice I can offer (for many reasons) is to walk away and stay with what you're doing.

 

[mysteryman]

Good luck with that.

Do as much reading and listening as you can. There are lots of characters on here who are only armchair experts, and much duff advice is given. There are others, myself included, who favour one particular approach and/or make of boiler. In my case, this is based upon many decades in the business, and a good knowledge of boiler design and control systems.

However, the first thing you need to do here is to find out how much water the cold main can provide. Any combi or unvented hot water supply requires the cold main to provide the total flowrate for all taps, hot and cold, which are running at a time. Otherwise, you will need storage tanks, possibly with a pump boost set, or an accumulator.

Study the job and the people well, and only take it on if you are sure it is right for you. We all had our first central heating job at some time!

 

[hamel0178]

Thanks for advise mysteryman

 

[dcawkwell]

Not doubting your ability to do the job, but the best advice I can offer (for many reasons) is to walk away and stay with what you're doing.

Well no one would get anywhere if we all did this.