System Boiler Advice

[thunderstruck]

Hi all,

Purchasing a new property and I have a few questions for you. But first a bit of context.

At the moment, there is a boiler with a cylinder in the kitchen, and another cylinder in the loft. I don't know if it's a heat-only boiler or a system boiler but I assume it's the former given the two cylinders. I may be completely wrong here.

The property is a detached house with three bedrooms and two bathrooms (one with a shower and one with both shower & bathtub). This is the current situation, but in a few years I am looking to do a loft conversion which will result in an additional bedroom and additional bathroom with definitely a shower and potentially another bathtub.

I am thinking of renovating the boiler and I have the following few questions:

• Am I correct thinking that I need a system boiler or can I get away with a combi?
• Assuming there is a heat-only boiler and I move to a system boiler, do I keep the existing cylinder, or should I opt for a new one?
• Assuming I go for a new complete system boiler, which one would you suggest (boiler and cylinder) for the situation I described above?
• Anything else I am missing?

Property is in EN2 and I have no idea of the water pressure there unfortunately. If anyone has any information, I would appreciate it.

Thanks!

 

[Deleted member 120897]

Good evening thunderstruck,

You’ll need to have your pressure and flow rate measured. Based on some of the information provided, a Combi sounds unsuitable for your requirements - and would be probably best suited to an unvented cylinder - which can be heat only or system boiler.

 

[thunderstruck]

Good evening thunderstruck,

You’ll need to have your pressure and flow rate measured. Based on some of the information provided, a Combi sounds unsuitable for your requirements - and would be probably best suited to an unvented cylinder - which can be heat only or system boiler.

Thank you for your reply.

I had a conversation with another friend this afternoon who suggested that I keep the heat-only set up as the additional pressure from a system boiler may burst the existing pipes. Never thought about that, so I need to understand the current pressure as you mentioned and flow rate.

I assume that's a plumber who would do that (total ignorance here). Any idea how much that would cost?

 

[Deleted member 120897]

I assume that's a plumber who would do that (total ignorance here). Any idea how much that would cost?

If you’re referring to the pressure and flow rate, then yes generally a plumber. If you’re referring to an unvented cylinder, this would be a G3 registered plumber/engineer.

Regards cost - absolutely no idea as they vary countrywide. If need be obtain 3 quotes.

 

[Ric2013]

Unlikely that the existing pipework would not accept mains pressure, though always possible.

You can probably keep your existing cylinders if you want. You can even get a combi and run some taps from the combi and others (the bath perhaps) from a cylinder.

And you are completely wrong to assume boiler is heat only by the way just because it feeds a hot water cylinder. The presence of a smallish (4 gallonish) CISTERN, however, would almost certainly indicate a heat only boiler.

A heat only boiler does not contain means of expansion nor a pump, a system boiler does - that is the only difference. Either type can be connected to an open-vented cylinder (the latter will be fed by a largish (25gallons+) cistern).

If you truly mean two cylinders, one may be a thermal store such as a Gledhill Boilermate?

 

[king of pipes]

A few pictures would put us on the correct path to helping you ? I will hold back until then . Kop

 

[thunderstruck]

Thank you all for the replies.

I don't have any photos at the moment, and I am waiting for the completion so I can actually get into the property and provide some proper photos.

With regards to the cylinders, I did notice a big one next to the boiler (in the kitchen) and another big one at the loft. Unfortunately I didn't notice a small one, but there may well be one there.

I think having a plumber looking at the whole system up close would be able to determine what the best route going forward is.

Any particular brands i should be considering and what kW?

 

[king of pipes]

I would say get a local company to take a look and be advised by them , older properties are sometimes a bit tricky maybe jot down your thoughts of the improvements you are planning to make and what you are hoping to achieve, 3 bathrooms although probably not all used at the same time ?, you will require a decent water supply with 3 bar + pressure and a good flow rate 21+ litres a minute for a unvented type cylinder, a dedicated supply straight to the cylinder from the incoming supply this may not be achievable so a survey needs to be carried out to find your options . Regards kop

 

[thunderstruck]

Thank you kop, really appreciate the advice.

 

[gmartine]

Pictures are really required for a proper assesment from us as we can't rely on your description...you may already have an unvented cylinder in the kitchen and a simple upgrade might do when it comes to extending the house further.

 

[gmartine]

Just to add, don't get too hung up on boiler type as any of them can all be made to work with an unvented cylinder with the right controls, your chosen installer should know how and why. Steer clear of combi slappers that'll say it'll be fine but only if it's large enough, some storage combi's might do for a 3+ bathroom residence but you still need the requisite gas and water pressures as you would with an unvented cylinder.

I'd go as far as saying opt for a gas engineer with a commercial ticket if you're really serious about expanding your hot water requirements in the manner and quantity that you say you are. You've spent £100,000's on a new property, will spend £10,000's on an extenension/conversion to give you many baths and showers so don't skimp or think you can on your hot water delivery system if you want a decent result.

 

[thunderstruck]

Just to add, don't get too hung up on boiler type as any of them can all be made to work with an unvented cylinder with the right controls, your chosen installer should know how and why. Steer clear of combi slappers that'll say it'll be fine but only if it's large enough, some storage combi's might do for a 3+ bathroom residence but you still need the requisite gas and water pressures as you would with an unvented cylinder.

I'd go as far as saying opt for a gas engineer with a commercial ticket if you're really serious about expanding your hot water requirements in the manner and quantity that you say you are. You've spent £100,000's on a new property, will spend £10,000's on an extenension/conversion to give you many baths and showers so don't skimp or think you can on your hot water delivery system if you want a decent result.

Thank you.... spot on. I have reached out to a gas engineer as suggested to get a proper look at the system and determine next steps