Bartimaeus

We had no plan to set off from Stone on the day we returned from Edinburgh.  Instead we took the opportunity to restock the fridge and larder from the high-class supermarket (no other high-class supermarkets are available nearby). 

Another reason not to rush on was an appointment with Nick from Hydrogen Afloat the next day.  He was bringing another Modbus board to install in to the Kensa heat pump.  This one had been tested successfully at Ortomarine HQ.  Once it was in place the behaviour seemed little different, however a quick phone call to Rob allowed him to make some changes.  With those changes made we confirmed that two-way data transfer was at last functional.

It is a small step, but being able to read the temperatures of the four pipes at the back of the heat pump is vital for understanding how well it is performing.  (The four are the "flow" and "return" for each of the "source" and "load".  The source is the circuit that includes the skin tank which allows us to take heat out of the canal, the load is the radiators or hot water tank which get that heat.)

We set off in the afternoon out of Stone and through the four locks in sunshine. After a mile or so we passed a private wharf.

The first time we came this way, I spotted this lock marked on my map and had Clare get ready to operate it.  The next time, I didn't repeat the mistake, but I did notice a for sale sign and wondered if the boat was being sold too. Last month, Lodestar was heading out of a lock in front of us just as another boat was arriving.  The incoming boater knew more of their story.  The owners of Lodestar had re-excavated the filled-in wharf for their use many years ago.  They had now sold the house, but lived nearby and retained the use of the mooring.

We moored up a little further along the canal. Before I did the washing up later on I made a minor upgrade.  When we first got aboard Bartimaeus we discovered there was no plug for the sink.  I found one five years ago, but this year it has been leaking.  Doing the washing up before the water runs out is frustrating.  A new one cost less than a cup of coffee - and what a difference it makes!

The next morning it was raining, but forecast to be dry in the afternoon.  I made some bread and made a point of running the generator to recharge the batteries while the oven was on.  We drove on in the afternoon sunshine spotting a kingfisher.  Clare did the only lock of the day.  The lock arm had an unusual guard rail on the end - preventing a long fall.

When Nick had visited he had asked if we had seen a special spanner which he thought had been left on board for our use.  Neither of us remembered seeing it, but he had checked with his colleague and asked me to check in the cupboard next to the heat pump.  When we had moored up I checked but found nothing.  What I did notice was the big folder with all sorts of technical stuff about the boat.  In the plastic envelope containing things relating to the recent upgrade I found the spanner!

The spanner is used to open the top of the magnetic filter for the heat pump's source side circuit.  It collects stray metal such as that left behind after the skin tank has been welded.

I cut down a milk carton to catch the fluid and then turned off the two valves before removing the magnet from its housing.  The plastic covering of the magnet at first looked like it was covered in oil, but as the fluid ran off, the dark patches turned out to be tiny fragments of metal, soon cleaned off.

The sunny evening gave way to a clear night and dropping temperatures, I didn't really notice until I started feeling cold.  We still don't have automatic control of the heat pump, but I can turn it on manually. I quickly gave up on running the radiators at very low temperatures and returned to the default of 40°C.  The boat slowly warmed up, but to use a heat pump at its most efficient it is best not to let things get cold.

This morning was bright again and forecast to be sunny all day.  I set the generator running again as we walked through the woods to the Wedgwood Factory we had passed yesterday.  We joined a tour of the factory - a much smaller place than I expected, and with much less automation than I was expecting.  Afterwards we had Staffordshire Oatcakes in the cafe - a local speciality, very similar to a pancake or crepe.

Back on board we set off again.  The promised full sunshine was interspersed with very dark clouds but the afternoon stayed dry and we spotted another kingfisher.  I had remembered the Stoke Locks as being very tough so offered to work them.  Either my memory is poor or there has been some excellent maintenance - all the gates and paddles bar one were easy to operate.  Some were covered in spectacular graffiti too.

We have been running close to the railway for many miles, but never quite as close as at one of the locks.  There was just enough room to get up the steps to operate the lock.  The towpath for anyone not needing to get to the tail gates runs under the railway to the top end of the lock.

We reached the summit at Etruria just as the rain started.  We needed to get here to use several of the facilities, but they can all wait until tomorrow when it should be drier.

The air has been cold today, so for the first time this year we have been driving with the rear cabin doors closed to keep the warmth in.  Soon after we moored up I started the heat pump with the radiator temperatures set to 35°C.  This has kept the cabin at a comfortable temperature while operating with an efficiency of greater than 450%.  The theory is that even when we generate our electricity with our generator, we are still able to get more warmth in the cabin than by burning the fuel directly to heat the radiators.  As the nights get colder we will learn more about the balance of that equation.