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Andrew Smith
Andrew Smith, Plumber
Category: Plumbing
Satisfied Customers: 3646
Experience:  City and Guilds qualified plumber
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I have a very old baxi patent back boiler on my open fireplace

Customer Question

I have a very old baxi patent back boiler on my open fireplace in the living room.
It is linked to the gravity side of my semi-gravity central heating system. I want to change to a fully pumped S plan system but I need to disable and puncture the back boiler or find another safe use for the heat e.g. fit radiators or a new tank. Can you provide advice for the options?
Submitted: 4 years ago.
Category: Plumbing
Expert:  Andrew Smith replied 4 years ago.

Andrew Smith :

Can you explain what you mean about semi-gravity?

JACUSTOMER-3evowp3m- :

One side of the boiler is pumped to the central heating radiators. The other side of the boiler is the hot water side and moves by heat convection. I want to make the system fully pumped for both ch and water. The s plan system uses one pump with at least two zone valves linked to thermostats to move the hot water to where the heat is needed. However I also have an open fire with a back boiler that links to the gravity side. I don't think I can keep this once the system is fully pumped as a power cut would close the valves and stop the pump. This would leave no way of dissipating the heat from the back boiler. I am looking for safe options. I would like to keep the back boiler but don't think I can. Have you any ideas?

Andrew Smith :

Ok, gravity hot water and pumped central heating.

Andrew Smith :

if you cap the domestic hot water side and use the use pipes to the cylinder cupboard as a flow and return

Andrew Smith :

you will have to adjust the vent and cold feed positions, but it is achievable

JACUSTOMER-3evowp3m- :

Please provide the information I requested regarding what to do with the flow and return from the back boiler. Can I keep this linked to the hot water cylinder? The info p[rovided so far

JACUSTOMER-3evowp3m- :

only tells me info that I had already know as this is the standard s plan layout that I referred to in the question. I need info on the open fireplace back boiler options.

Andrew Smith :

If you use the gravity pipes that feed the cylinder from the boiler and disconnect from the cylinder, fit the pump and motorised valves in the cylinder cupboard and then tee the heating flow into the heating circuit upstairs it should work.

Andrew Smith :

Disconnect the other side of the boiler and cap the tees