Oil to Gas Quote

newbieni

Hi,

The below is a quote I've received for an oil to gas conversion which includes five new radiators. Is it fair and what is the guarantee really worth if the firm goes out of business?

Thanks in advance 

Quotation for the installation of gas heating with Worcester Bosch boiler 

 New Worcester 30 KW 4000 Greenstar boiler to be located in the existing boiler house. 

 A new horizontal flue pipe shall be taken from the gas boiler and terminate through external wall. 

 New boiler house door is recommended. 

 New British standard COPPER tubing shall be neatly installed by our expert installers. 

 The five existing 50 year old radiators shall be replaced with Five new high output convector panel radiators complete with new thermostatic and lockshield valves. 

 The two Attic radiators shall be raised 150mm from the floor level. 

 Heating system is to be flushed and treated with necessary cleaning and anti-corrosion chemicals 

 A 28mm gas supply pipe shall be connected to the new boiler. A gas filter shall be installed below the boiler. 

 The gas boiler shall be wired to existing heating controls and programmer. 

 Boiler is to be commissioned in accordance with the manufactures instructions 

 On completion the heating system shall be flushed and chemically treated with Fernox. 

 All necessary wiring connections will be made by Action Plumbing and Heating 

 All work undertaken by Action Plumbing and Heating shall be guaranteed for 5 years, the industry standard is 2 years. 

Boiler specification

 Worcester Bosch 4000 Greenstar 30kW Boiler and Flue 

 8 Year Parts and Labour Guarantee 

 Labour & Materials Cost - £4850.00 

Budget Boiler Option: 

Worcester Bosh 1000 30 KW model with 5 year guarantee. £4550.00

Recommend upgrades:

Worsester Magnetic Filter - £195
Supply and fit of a plume kit - £145

Devongardener

If the quote includes all materials and labour, including the new radiators and the system flush, it sounds like a reasonable quotation.
The warranty for the boiler will be with the manufacturer not the installer, an annual service usually required to maintain the warranty.  

Albermarle

You do not mention the hot water supply. Is this a combi boiler?

As you are taking the step of changing fuel and boiler, changing radiators etc it could be a good time to consider a heat pump?

FreeBear

newbieni said:

 New Worcester 30 KW 4000 Greenstar boiler to be located in the existing boiler house. 

 The five existing 50 year old radiators shall be replaced with Five new high output convector panel radiators complete with new thermostatic and lockshield valves. 

 The gas boiler shall be wired to existing heating controls and programmer. 

Recommend upgrades:
Worsester Magnetic Filter - £195
Supply and fit of a plume kit - £145

For a combi boiler where our cold water flow rate is 12l/min, 30kW is about right. As a system boiler, way, way too big - A 12-14kW model would probably suffice at the expense of slightly longer reheat times for a hot water tank.

Radiators should be specified with a flow temperature as low as possible - If you go for 45°C, you'd be heat pump ready when the time comes. Meanwhile, the boiler will operate further in to condensing mode which will give you better fuel efficiency and reduce the effects of corrosion.

You should be fitting a new programmable thermostat that can talk to the boiler and allow for complete modulation control. This alone could save up to 15% on gas consumption. As for TRVs, I'm not convinced that they will save much energy, especially with just 5 radiators (see below).

A magnetic filter will be mandated by WB as part of their warranty. And if you are paying £5K, I'd be expecting a 10  or even 12 year guarantee, not a measly 5 year one.

I have 9 radiators with a total output of 13kW@70°C, but I never run that hot. Most of the time, the flow temperature is between 45°C and 55°C for a heat output of 6 to 9kW. As the thermostat gets close to the set point, flow temperature could drop to under 40°C for a ~4kW output. Minimum output of the boiler (a Viessmann 050) is 3.2kW (same as the Greenstar 4000). If TRVs start to operate and take one or more radiators out, the boiler starts to short cycle. This is bad for efficiency and long term reliability, so should be avoided.

The Viessmann talks OpenTherm, as does the thermostat/control. This allows for load compensation, so the boiler will modulate down depending on how much heat is required to keep the place warm - Rarely do I see more than ~8kW of heat being generated (have a heat meter next to the boiler). Most of the time it is ticking over at 4-6kW.

The only reason I have a 30kW boiler is because it is a combi. Even so, I could have gotten away with a 25kW model as my cold water flow rate is just over 10l/min.

With the (smarter) programmable thermostat, I'm able to achieve an overall efficiency of 94-95%. Considerably better than quoted 72% of the old Baxi back boiler that I did have.

newbieni

FreeBear said:

newbieni said:

 New Worcester 30 KW 4000 Greenstar boiler to be located in the existing boiler house. 

 The five existing 50 year old radiators shall be replaced with Five new high output convector panel radiators complete with new thermostatic and lockshield valves. 

 The gas boiler shall be wired to existing heating controls and programmer. 

Recommend upgrades:
Worsester Magnetic Filter - £195
Supply and fit of a plume kit - £145

For a combi boiler where our cold water flow rate is 12l/min, 30kW is about right. As a system boiler, way, way too big - A 12-14kW model would probably suffice at the expense of slightly longer reheat times for a hot water tank.

Radiators should be specified with a flow temperature as low as possible - If you go for 45°C, you'd be heat pump ready when the time comes. Meanwhile, the boiler will operate further in to condensing mode which will give you better fuel efficiency and reduce the effects of corrosion.

You should be fitting a new programmable thermostat that can talk to the boiler and allow for complete modulation control. This alone could save up to 15% on gas consumption. As for TRVs, I'm not convinced that they will save much energy, especially with just 5 radiators (see below).

A magnetic filter will be mandated by WB as part of their warranty. And if you are paying £5K, I'd be expecting a 10  or even 12 year guarantee, not a measly 5 year one.

I have 9 radiators with a total output of 13kW@70°C, but I never run that hot. Most of the time, the flow temperature is between 45°C and 55°C for a heat output of 6 to 9kW. As the thermostat gets close to the set point, flow temperature could drop to under 40°C for a ~4kW output. Minimum output of the boiler (a Viessmann 050) is 3.2kW (same as the Greenstar 4000). If TRVs start to operate and take one or more radiators out, the boiler starts to short cycle. This is bad for efficiency and long term reliability, so should be avoided.

The Viessmann talks OpenTherm, as does the thermostat/control. This allows for load compensation, so the boiler will modulate down depending on how much heat is required to keep the place warm - Rarely do I see more than ~8kW of heat being generated (have a heat meter next to the boiler). Most of the time it is ticking over at 4-6kW.

The only reason I have a 30kW boiler is because it is a combi. Even so, I could have gotten away with a 25kW model as my cold water flow rate is just over 10l/min.

With the (smarter) programmable thermostat, I'm able to achieve an overall efficiency of 94-95%. Considerably better than quoted 72% of the old Baxi back boiler that I did have.

Thanks, just to note - five radiators are being replaced we have about 10 in total.

FreeBear

newbieni said:

FreeBear said:

newbieni said:

 New Worcester 30 KW 4000 Greenstar boiler to be located in the existing boiler house. 

 The five existing 50 year old radiators shall be replaced with Five new high output convector panel radiators complete with new thermostatic and lockshield valves. 

 The gas boiler shall be wired to existing heating controls and programmer. 

Recommend upgrades:
Worsester Magnetic Filter - £195
Supply and fit of a plume kit - £145

For a combi boiler where our cold water flow rate is 12l/min, 30kW is about right. As a system boiler, way, way too big - A 12-14kW model would probably suffice at the expense of slightly longer reheat times for a hot water tank.

Radiators should be specified with a flow temperature as low as possible - If you go for 45°C, you'd be heat pump ready when the time comes. Meanwhile, the boiler will operate further in to condensing mode which will give you better fuel efficiency and reduce the effects of corrosion.

You should be fitting a new programmable thermostat that can talk to the boiler and allow for complete modulation control. This alone could save up to 15% on gas consumption. As for TRVs, I'm not convinced that they will save much energy, especially with just 5 radiators (see below).

A magnetic filter will be mandated by WB as part of their warranty. And if you are paying £5K, I'd be expecting a 10  or even 12 year guarantee, not a measly 5 year one.

I have 9 radiators with a total output of 13kW@70°C, but I never run that hot. Most of the time, the flow temperature is between 45°C and 55°C for a heat output of 6 to 9kW. As the thermostat gets close to the set point, flow temperature could drop to under 40°C for a ~4kW output. Minimum output of the boiler (a Viessmann 050) is 3.2kW (same as the Greenstar 4000). If TRVs start to operate and take one or more radiators out, the boiler starts to short cycle. This is bad for efficiency and long term reliability, so should be avoided.

The Viessmann talks OpenTherm, as does the thermostat/control. This allows for load compensation, so the boiler will modulate down depending on how much heat is required to keep the place warm - Rarely do I see more than ~8kW of heat being generated (have a heat meter next to the boiler). Most of the time it is ticking over at 4-6kW.

The only reason I have a 30kW boiler is because it is a combi. Even so, I could have gotten away with a 25kW model as my cold water flow rate is just over 10l/min.

With the (smarter) programmable thermostat, I'm able to achieve an overall efficiency of 94-95%. Considerably better than quoted 72% of the old Baxi back boiler that I did have.

Thanks, just to note - five radiators are being replaced we have about 10 in total.

OK, in which case, an 18kW system boiler would be suitable - You need to do a full heat loss calculation on each room. I use this one -> https://www.stelrad.com/basic-heat-loss-calculator/ with a mean water temperature of 40-45°C (this equates to a flow temperature of 45-55°C). You will find that the sizes will be quite a bit bigger than your engineer is recommending, but larger is not a bad thing.

Once you know what the total heat load is on the boiler, you can select an appropriately sized one - Smaller boilers running at a higher load percentage will be more efficient than a massively oversized one that is constantly short cycling (and a little cheaper to boot).