Water Meter system boiler vs combi

Kiran

Steveotwo said:

Kiran said:

Other things that might be worth considering. A system boiler gives you the additional options of being able to take advantage of solar thermal amd solar PV to heat water, it allows you to benefit from agile pricing if you use cheap rate electricity to heat your tank. I'd go as far as to say the cylinder and controls are on par with respect to the amount they can save you over just changing a functional boiler for a new one

How would I go about adding these solar options? I always thought these where very expensive?

So, couple of ways to benefit from solar, one is to change your cylinder for a cylinder with solar thermal coils. I was having a new cylinder added anyway as I have multiple people getting ready at the same time in the morning etc. so the tank means you can pull hot water from multiple outlets. Not an option with a combi unfortunately. The cost of the multi coil cylinder wasn't much different from the standard high efficiency cylinder. The panels work out about £500ish each (trade). From about May to September the solar thermal takes care of almost all the hot water need.

The other way to benefit is to have solar PV and use the electricity generated to power the immersion. During the winter I use this approach, the solar thermal still adds a bit on the odd sunny days. You can also use cheap rate electricity if you are on an agile tariff and occasionally get paid to heat your tank.

Varying levels of investment from free if you alter your electricity tariff, to reasonable investment for solar thermal to expensive if you go for a full PV array which benefits you in multiple other ways too

Albermarle

 I was having a new cylinder added anyway as I have multiple people getting ready at the same time in the morning etc. so the tank means you can pull hot water from multiple outlets. Not an option with a combi unfortunately.

Even if you have a hot water tank, multiple outlets only really works if you have an unvented system and a good mains pressure.
If you have a vented system and/or not very good mains pressure, then turning on one outlet tends to reduce flow to another. Although with a vented system, shower pumps will help with those outlets.

Steveotwo

Kiran said:

Steveotwo said:

Kiran said:

Other things that might be worth considering. A system boiler gives you the additional options of being able to take advantage of solar thermal amd solar PV to heat water, it allows you to benefit from agile pricing if you use cheap rate electricity to heat your tank. I'd go as far as to say the cylinder and controls are on par with respect to the amount they can save you over just changing a functional boiler for a new one

How would I go about adding these solar options? I always thought these where very expensive?

So, couple of ways to benefit from solar, one is to change your cylinder for a cylinder with solar thermal coils. I was having a new cylinder added anyway as I have multiple people getting ready at the same time in the morning etc. so the tank means you can pull hot water from multiple outlets. Not an option with a combi unfortunately. The cost of the multi coil cylinder wasn't much different from the standard high efficiency cylinder. The panels work out about £500ish each (trade). From about May to September the solar thermal takes care of almost all the hot water need.

The other way to benefit is to have solar PV and use the electricity generated to power the immersion. During the winter I use this approach, the solar thermal still adds a bit on the odd sunny days. You can also use cheap rate electricity if you are on an agile tariff and occasionally get paid to heat your tank.

Varying levels of investment from free if you alter your electricity tariff, to reasonable investment for solar thermal to expensive if you go for a full PV array which benefits you in multiple other ways too

Thanks can you point me to any videos of these set ups? How much was it to get it all wired in after paying £500 for the panels?

jennifernil

JohnSwift10 said:

When I had a hot water tank I used 3kWh a day for the pilot light and 7 kWh a day to heat the water.
After I got a combi boiler my daily use (in the summer without the heating being on) is about 11 kWh a day so no difference in gas usage overall  but I am using more gas to heat the water water.

As for water use I have no idea as I live in Scotland and we don't get the option to have water meters.and I am paying £667.81 a year for water used by 2 OAPs

We are also in Scotland and paying almost £900 for water for 2 OAPs.    You can get a water meter if you want, look it up on the Scottish Water website, but it costs to get it to start with and they do not make it easy!   One could be forgiven for thinking that SW really do not want people to have them.

Kiran

Steveotwo said:

Another question then, lets say it breaks today and cannot be repaired. A heat pump is unaffordable to me right now, would replacing with just a modern system boiler be more cost effective given its cheaper than upgrading to a combi system? Are modern system boilers much more efficient? @Kiran @FreeBear

Modern boilers are more efficient than old boilers. FreeBear has dealt with that one above. If your old boiler isn't condensing then you will definitely get a better efficiency on your fuel if you are able to lower your flow temperature down it will spend more time condensing. 

Steveotwo

Kiran said:

Steveotwo said:

Another question then, lets say it breaks today and cannot be repaired. A heat pump is unaffordable to me right now, would replacing with just a modern system boiler be more cost effective given its cheaper than upgrading to a combi system? Are modern system boilers much more efficient? @Kiran @FreeBear

Modern boilers are more efficient than old boilers. FreeBear has dealt with that one above. If your old boiler isn't condensing then you will definitely get a better efficiency on your fuel if you are able to lower your flow temperature down it will spend more time condensing. 

Are modern System boilers condensing to I thought it was only Combi's

BarelySentientAI

Steveotwo said:

Kiran said:

Steveotwo said:

Another question then, lets say it breaks today and cannot be repaired. A heat pump is unaffordable to me right now, would replacing with just a modern system boiler be more cost effective given its cheaper than upgrading to a combi system? Are modern system boilers much more efficient? @Kiran @FreeBear

Modern boilers are more efficient than old boilers. FreeBear has dealt with that one above. If your old boiler isn't condensing then you will definitely get a better efficiency on your fuel if you are able to lower your flow temperature down it will spend more time condensing. 

Are modern System boilers condensing to I thought it was only Combi's

All gas boilers fitted since April 2005 (and oil boilers since April 2007) are condensing.

ComicGeek

Steveotwo said:

Kiran said:

Steveotwo said:

Kiran said:

Other things that might be worth considering. A system boiler gives you the additional options of being able to take advantage of solar thermal amd solar PV to heat water, it allows you to benefit from agile pricing if you use cheap rate electricity to heat your tank. I'd go as far as to say the cylinder and controls are on par with respect to the amount they can save you over just changing a functional boiler for a new one

How would I go about adding these solar options? I always thought these where very expensive?

So, couple of ways to benefit from solar, one is to change your cylinder for a cylinder with solar thermal coils. I was having a new cylinder added anyway as I have multiple people getting ready at the same time in the morning etc. so the tank means you can pull hot water from multiple outlets. Not an option with a combi unfortunately. The cost of the multi coil cylinder wasn't much different from the standard high efficiency cylinder. The panels work out about £500ish each (trade). From about May to September the solar thermal takes care of almost all the hot water need.

The other way to benefit is to have solar PV and use the electricity generated to power the immersion. During the winter I use this approach, the solar thermal still adds a bit on the odd sunny days. You can also use cheap rate electricity if you are on an agile tariff and occasionally get paid to heat your tank.

Varying levels of investment from free if you alter your electricity tariff, to reasonable investment for solar thermal to expensive if you go for a full PV array which benefits you in multiple other ways too

Thanks can you point me to any videos of these set ups? How much was it to get it all wired in after paying £500 for the panels?

Forget about solar thermal - it's expensive to install, difficult to maintain and very limited savings. Hot water usage is pretty small in most cases so the savings are very small - once the cylinder is heated up in the summer you can't use the excess generation anywhere else. Most houses could save an average of £60 per year with solar thermal - typical installation costs of around £4-5k, so never going to pay back. The high pressure systems tend to overheat in summer and autovent - the cost of maintenance and refilling is more expensive than any running cost saving. 

Solar photovoltaics to produce electricity are a much better option, as you can choose where to use the electricity - you can heat the cylinder via immersion, run the washing machine, charge the car etc. But again is unlikely to provide a reasonable payback unless you get a really good deal or are a high summer electricity user (ie running air con, swimming pool etc).

Spend money on heating controls. Don't spend any money replacing an existing working boiler with another. Definitely don't replace an existing working system boiler and cylinder with a combi.

Steveotwo

ComicGeek said:

Steveotwo said:

Kiran said:

Steveotwo said:

Kiran said:

Other things that might be worth considering. A system boiler gives you the additional options of being able to take advantage of solar thermal amd solar PV to heat water, it allows you to benefit from agile pricing if you use cheap rate electricity to heat your tank. I'd go as far as to say the cylinder and controls are on par with respect to the amount they can save you over just changing a functional boiler for a new one

How would I go about adding these solar options? I always thought these where very expensive?

So, couple of ways to benefit from solar, one is to change your cylinder for a cylinder with solar thermal coils. I was having a new cylinder added anyway as I have multiple people getting ready at the same time in the morning etc. so the tank means you can pull hot water from multiple outlets. Not an option with a combi unfortunately. The cost of the multi coil cylinder wasn't much different from the standard high efficiency cylinder. The panels work out about £500ish each (trade). From about May to September the solar thermal takes care of almost all the hot water need.

The other way to benefit is to have solar PV and use the electricity generated to power the immersion. During the winter I use this approach, the solar thermal still adds a bit on the odd sunny days. You can also use cheap rate electricity if you are on an agile tariff and occasionally get paid to heat your tank.

Varying levels of investment from free if you alter your electricity tariff, to reasonable investment for solar thermal to expensive if you go for a full PV array which benefits you in multiple other ways too

Thanks can you point me to any videos of these set ups? How much was it to get it all wired in after paying £500 for the panels?

Forget about solar thermal - it's expensive to install, difficult to maintain and very limited savings. Hot water usage is pretty small in most cases so the savings are very small - once the cylinder is heated up in the summer you can't use the excess generation anywhere else. Most houses could save an average of £60 per year with solar thermal - typical installation costs of around £4-5k, so never going to pay back. The high pressure systems tend to overheat in summer and autovent - the cost of maintenance and refilling is more expensive than any running cost saving. 

Solar photovoltaics to produce electricity are a much better option, as you can choose where to use the electricity - you can heat the cylinder via immersion, run the washing machine, charge the car etc. But again is unlikely to provide a reasonable payback unless you get a really good deal or are a high summer electricity user (ie running air con, swimming pool etc).

Spend money on heating controls. Don't spend any money replacing an existing working boiler with another. Definitely don't replace an existing working system boiler and cylinder with a combi.

Thank you sir, so I keep the existing one, update my controls. With it been likely 70% efficent I should just expect my month to month bills to increase a smidge?

MysteryMe

Apologies if I have the wrong poster, I think you are the poster who had just moved in to a larger home that had a fully working boiler but was naturally concerned about energy costs over winter?

I think my original advice still stands TBH. See how your bills are for one winter, before spending thousands to potentially only saving hundreds.  You are then dealing with what is known rather than what may or may not be.

Concentrate on insulation, thermostat controls etc.