Combi vs tank - which should I go for?

[b21playa]

If a thorough calculation is completed you will arrive at the most accurate result. Having said that there are often cases where the homeowner just doesn’t know what, if any insulation is present. Times like that you would use quick reference guides but as I said above these can be way off at times. Once you have an idea of your loads then you can start designing the system. Is the customer happy with a high temperature system? Or do they want to maximise efficiency as much as possible and have a low temperature system installed and so on and so on. Before any of this can be decided and priced up and quoted for you need those initial heat loss figures.

Hi

This is my own house, looking for get heat into it. It takes hours for it to heat up, our previous house was never like this.

 

[SJB060685]

Yes I know mate. My questions were generic ones not specifically asking you . Excuse my ignorance but didn’t you create a post the other day about pipe sizes feeding radiators?

 

[b21playa]

Yes I know mate. My questions were generic ones not specifically asking you . Excuse my ignorance but didn’t you create a post the other day about pipe sizes feeding radiators?

Yes I did pal. I’m trying to plan everything and changing radiators while I’m sorting a few rooms out downstairs. The boiler/tank will be changed before kitchen is completed as it’s currently in a cupboard in there. Hot water flow is not good and I’d like to remove tanks in the loft

 

[SJB060685]

Yes I remember that post and that your current system is a shambles. To be honest from what I remember of the other post is if any of those that have used your existing system as a reference to supply you with a quote so far then forget them. You need a good installer/firm who are going to do everything required and thoroughly.

 

[b21playa]

Yes I remember that post and that your current system is a shambles. To be honest from what I remember of the other post is if any of those that have used your existing system as a reference to supply you with a quote so far then forget them. You need a good installer/firm who are going to do everything required and thoroughly.

All figures are based off calculate I’ve used. You’re right the existing system is no good so I’ve disregarded everything in it, everything needs renewing, apart from pump and zone valves which are 3yrs old

 

[b21playa]

Just tested water pressure at washing machine fitting @ 4bar static

 

[ShaunCorbs]

And flow rate eg how long to fill a 1 or 2 l bottle at full open

 

[b21playa]

And flow rate eg how long to fill a 1 or 2 l bottle at full open

Flow rate was approx 22lpm measured with flow cup

 

[ShaunCorbs]

That’s perfect for an unvented

 

[b21playa]

That’s perfect for an unvented

Thanks for that, great to hear.

Only issue I have is I’ve read cold mains should go to cylinder first and then balanced off to taps. As my mains comes up in the kitchen and already connected to everything first, will this cause an issue?

Also what’s the recommended boilers these days. I have a valiant 438 which came with the house and heard they are not the best. Is this the same for a 637 and should I look at a different manufacturer

Thanks again

 

[ShaunCorbs]

Just fit the combo valve eg prv at your mains stop tap or a secondary pressure reducer to keep the whole system at the same pressure

First thing to do is get a heat loss done then you know the load of the new boiler

 

[b21playa]

Just fit the combo valve eg prv at your mains stop tap or a secondary pressure reducer to keep the whole system at the same pressure

First thing to do is get a heat loss done then you know the load of the new boiler

So I do have an option, although looking to replace the lead mains with mdpe and have the stopcock relocated. All depends on cost as it’s around 30m run to the street from the front of the garage.

Can I do the heat loss calcs myself? Just trying to save a bit of cash as everything is mounting up. I can then get someone to come and fit & commission boiler and tank

 

[ShaunCorbs]

What’s your budget for the whole ?

 

[b21playa]

What’s your budget for the whole ?

Probably not enough but will be done slowly. Was hoping £5k for everything

 

[ShaunCorbs]

As your system is working atm I would get the water main done first as it’s lead you might be able to get a deduction from the water board