Sunseeker 75 calorifier thermostat

S

S75rich

New Member
Joined
27 Mar 2021
Messages
19
Visit site
Good morning all,
I’m having trouble with the hot water on our boat, the thermostat appears to look like a radiator valve but has a probe that disappear into the cylinder.
I understand how this system works, what I can’t understand is how to change that probe.. initially it appears to be in “behind” the immersion, but I removed the immersion and it disappears down beside the threaded sleeve the immersion screws into. Logic would state that is a welded part of the calorifier so can’t be removed also .. any ideas how to get it out to change it?

thanks in advance
Bad picture but you can just see the silver probe by the immersion
ADC2A0CB-FF52-4A6C-B365-F5BD2A33FA46.jpeg
 
Bit confused....are talking about the “radiator” type valve you twist? Red with a chrome top?

whats the problem you’re try to solve
 
That’s exactly the part I’m talking about, it takes its temperature reading from a capillary tube set into the calorifier and it’s that capillary tube I don’t know how to remove

the issue is the thermostat isn’t controlling the flow of cooling water allowing the domestic water to reach an unbearable temperature
 
Take those red things out , they are the heating elements on 220/240 V .Inside separate will be the replaceable thermostats , but it’s up to you depending on age wether to just replace the job lot ?
Any household plumbing/ builder merchants store .
Turn off the 220/240 v at the breaker and for extra safety un plug the shore power .

If it’s not this put a circle on the image of what you are trying to remove / replace to get the hot water going .

Grey tap which is cold in .Turn it Off , use the cock at the bottom with a hose attached to drain the system down before unscrewing the “ elements “ or simply changing the thermostat s .The thermostats will have a dial on to set the water temp say 65 or 55 or what ever .

That Red / chrome top valve looks like hot out supply ?

What problem are trying to fix ?
 
Last edited:
The silver capillary is the heat sensor for the Drayton thermostat that is controlling the heating of the hot water indirectly from the engine. The sensor can be in a pocket fitted into the cylinder or just jammed between the insulation and the internal surface to sense the heat of the hot water. It won’t have water in it. If you can’t remove it, and you intend to replace the remote thermostat head just cut it off and fit the new probe into the space under the insulation.
 
S75rich said:
That’s exactly the part I’m talking about, it takes its temperature reading from a capillary tube set into the calorifier and it’s that capillary tube I don’t know how to remove

the issue is the thermostat isn’t controlling the flow of cooling water allowing the domestic water to reach an unbearable temperature
Click to expand...
The thermostat (s) have failed under the red caps so the elements are not turning off .
About @£20 each , or as said replace ( depending on age ) the whole units elements + t sats .
 
S75rich said:
That’s exactly the part I’m talking about, it takes its temperature reading from a capillary tube set into the calorifier and it’s that capillary tube I don’t know how to remove

the issue is the thermostat isn’t controlling the flow of cooling water allowing the domestic water to reach an unbearable temperature
Click to expand...

not sure you have the right idea.

turn of 240v to it......under the red cap of the elements, there is usually a little dial to set temp it cuts out at as they have an inbuilt thermostat. The water is heated to say....80c then your mixer (radiator chrome top thing) controls flow of 80c water in with cold supply and you get 45c at the tap Etc.....

I can’t imagine that sort of flow regulator ”reads” anything temp wise. Could just be stuck open to the hot side
 
Thanks for all the replies but it’s not the immersion heaters that I’m trying to solve, it’s the thermostat that controls the heat for the engine heated side of the system..
I’ve changed the immersions out of good practise, but am having the issue when running on engine heating not electric heating
As per my original post the question I have is

How do I remove the capillary tube for the radiator valve style thermostat
 
Mr Googler said:
not sure you have the right idea.

turn of 240v to it......under the red cap of the elements, there is usually a little dial to set temp it cuts out at as they have an inbuilt thermostat. The water is heated to say....80c then your mixer (radiator chrome top thing) controls flow of 80c water in with cold supply and you get 45c at the tap Etc.....

I can’t imagine that sort of flow regulator ”reads” anything temp wise. Could just be stuck open to the hot side
Click to expand...

that’s not correct.
The radiator style valve starts and stops the flow of coolant water from the engine to maintain the correct temperature of hot water in the calorifier which is the issue I am having heating off the engine.
The radiator style valve is not stopping the flow of engine coolant meaning the water is getting to hor
 
You’re right....it’s not correct...... now you’ve explained the actual issue!

Never heard of that setup...hopefully someone expert will be along. Still don’t understand what the capillary tube does. If the valve is a true thermostat.....what does it need a tube for?
 
S75rich said:
that’s not correct.
The radiator style valve starts and stops the flow of coolant water from the engine to maintain the correct temperature of hot water in the calorifier which is the issue I am having heating off the engine.
The radiator style valve is not stopping the flow of engine coolant meaning the water is getting to hor
Click to expand...

As somebody else has said. Get a complete new thermostat with capillary attached, cut the old one off. Fit the new valve & tuck the new capillary under the tank insulation.

Usually, if that stat fails, the water from the engine cooling circuit (could be 90c) heats the tank too hot.

Normally the complaint is no hot water when on shorepower, it has tripped the resettable overheat stat in the immersion heater.
 
Theres a chrome ring(nut) between the head, the plastic bit, and the body, the metal bit. Undo that ring, theres a brass pin in the centre. Get a hammer handle, dont hit it, just use the handle to gently depress the pin a few times . It should bounce back up. If yes, sorted, if no get a Drayton TRV 4 vale with 2m capilary sensor , the STRAIGHT model, and fit it. You may wish to try just a new head first...............no water involved, or if no then drain off and fit a new body too. Be sure to observe the flow direction, the arrow on the body, and all will be well.
 
S75rich said:
That’s exactly the part I’m talking about, it takes its temperature reading from a capillary tube set into the calorifier and it’s that capillary tube I don’t know how to remove

the issue is the thermostat isn’t controlling the flow of cooling water allowing the domestic water to reach an unbearable temperature
Click to expand...
I have a 175 liter hot water tank on my Manhattan 60 that looks virtually identical to yours. (Ordered the larger capacity tank when I had the boat built)

If you remove the item in question you will probably find it jammed with light brown gung that stops the spring and valve operating.

On my tank there is also a identical valve but with a black cover showing instead of the red, but with the same chrome top.

In Mallorca they are obtainable from the local plumbers merchant and not expensive,

My boat is in Cala d'or and due to the poor mains water I have to change these valves very 3-5 years . Not a big job.

The tanks are manufactured for Sunseeker by 'Surejust' in the Isle of Wight tel. 01983 400 464 contact David Battle. They can supply the parts and call them 'Hot water pressure relief valves (5 bar).

If you are still not sure it may be best to talk to the Sunseeker factory direct who have always been very keen to help, You will need the boats HIN number.
 
So just to update, the body of the radiator style valve is fully functioning, and I’m certain the capillary tube is the issue..
But here is my issue, the capillary tube disappears into the cover of the tank between the stainless outer skin and the immersion flange with no obvious way to remove it other than drilling the rivets and removing the outer stainless end cover?
Thoughts?
 
As I’ve said in various number of my posts and in my photos that calorifier is completely clad in a stainless steel jacket.. other than cutting a reasonable amount of the stainless external cladding to gain access to the internal copper tank how do you suggest I “tuck” a new capillary bulb inside the tank?
 
You must log in or register to reply here.

Share this page

Top