When we moved in to this house a few years ago I wasn’t familiar with oil fired or biomass boilers in any way at all. This was the system that greeted us:
Look at the size of that water tank on the right of the image! 3,000 litres apparently; it’s an accumulator tank, a sort of battery storage of hot water which is critical for the log boiler to operate safely and efficiently as you can't just switch it off like you can with an electric, gas or oil boiler.
Initially we just fed it heating oil and got on with other jobs around the house as you do when you first move in. However, I was shocked at how much heating oil the system consumed, probably around 1,800 litres between November to February. That was due to a few factors – we treated the house like our old place where I’d just replaced the gas boiler which was really efficient and cheap to run and that house was really well insulated. This house was larger, not as well insulated and in a much colder climate than the previous and of course those were the winter months. The other factors of high oil consumption were down to the lack of maintenance and existing faults ignored by the previous owner. Some faults were downright dangerous too.
We used the log boiler often and it was a novelty at first but with having to clean it so often it became quite the chore. The water temperature when running the log boiler was noticeably hotter, through the radiators and domestic hot water, with the latter becoming too hot more often than not. At one point the hot water was more than 80C at the tap. Dangerous and wasteful.
I needed to optimise the system to reduce the oil consumption and tame the log boiler but then covid hit. Getting a knowledgeable and dependable plumber in to check the system was nigh on impossible even after the lockdowns. One plumber did grace us with his presence but didn’t come back! Well, I'm not a plumber but I’m a multidisciplined engineer so I thought it’s time to research and understand the system and just do it myself.
I installed a Hive Thermostat system to replace the ancient Horstmann controller and the inaccurate dial type thermostats. This did improve things due to the greater granularity of settings and much more accurate temperature detection, but more could be done.
First, the understanding the plumbing. I traced each pipe and made a pretty picture:
Then I traced the wires for each component to determine their purpose. For example, how does the oil boiler know not to come on when the log boiler is running? Pipe thermostat!
The cable diagram is good for faulting and wiring but for understanding the circuit I simplified it:
I’ll post more later with what I have done already, the faults I’ve fixed and what I still plan to do. Hope you find it as interesting as I do
.
Edit: Reduced schematic images sizes.
Look at the size of that water tank on the right of the image! 3,000 litres apparently; it’s an accumulator tank, a sort of battery storage of hot water which is critical for the log boiler to operate safely and efficiently as you can't just switch it off like you can with an electric, gas or oil boiler.
Initially we just fed it heating oil and got on with other jobs around the house as you do when you first move in. However, I was shocked at how much heating oil the system consumed, probably around 1,800 litres between November to February. That was due to a few factors – we treated the house like our old place where I’d just replaced the gas boiler which was really efficient and cheap to run and that house was really well insulated. This house was larger, not as well insulated and in a much colder climate than the previous and of course those were the winter months. The other factors of high oil consumption were down to the lack of maintenance and existing faults ignored by the previous owner. Some faults were downright dangerous too.
We used the log boiler often and it was a novelty at first but with having to clean it so often it became quite the chore. The water temperature when running the log boiler was noticeably hotter, through the radiators and domestic hot water, with the latter becoming too hot more often than not. At one point the hot water was more than 80C at the tap. Dangerous and wasteful.
I needed to optimise the system to reduce the oil consumption and tame the log boiler but then covid hit. Getting a knowledgeable and dependable plumber in to check the system was nigh on impossible even after the lockdowns. One plumber did grace us with his presence but didn’t come back! Well, I'm not a plumber but I’m a multidisciplined engineer so I thought it’s time to research and understand the system and just do it myself.
I installed a Hive Thermostat system to replace the ancient Horstmann controller and the inaccurate dial type thermostats. This did improve things due to the greater granularity of settings and much more accurate temperature detection, but more could be done.
First, the understanding the plumbing. I traced each pipe and made a pretty picture:
Then I traced the wires for each component to determine their purpose. For example, how does the oil boiler know not to come on when the log boiler is running? Pipe thermostat!
The cable diagram is good for faulting and wiring but for understanding the circuit I simplified it:
I’ll post more later with what I have done already, the faults I’ve fixed and what I still plan to do. Hope you find it as interesting as I do
.Edit: Reduced schematic images sizes.
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. Having it partially open relieves some of that pressure/flow at the cost of some heat being returned to the system.
or big by London standards, and as for being remote I'm in the depths of the Scottish Highlands where I'm closer to Norway than I am to London 
. On inspection the valve body itself was in the open position and would open and closed perfectly fine by hand but the motorised actuator itself wouldn't mate with the shaft/spindle of the valve, the actuator was too worn. So when the actuator tried to open or close the valve it had no effect.
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