Type: PEX pipe system
Age: ~28 years (installed around 1996-1997)
Status: Unused for ~10 years
Condition: Likely serviceable
The house has an existing underfloor heating system throughout, installed when the house was built approximately 28 years ago.
Advantages:
- Even heat distribution
- Comfortable warmth
- Energy efficient (especially with heat pumps)
- No radiators taking up wall space
- Ideal for heat pump operation (lower water temps)
For Our Project:
- Already installed - major cost savings
- Perfect for eventual heat pump upgrade
- Just needs reconnection and testing
- No need to install new heating distribution
PEX = Cross-linked Polyethylene
Modern plastic piping used for water systems
- Lifespan: 50+ years for pipes from 2000s
- Unused storage: Can sit unused without degradation
- Resistance: Doesn't corrode, resistant to scale buildup
- Flexibility: Handles freezing better than copper
- Installed around 1996-1997 (28 years ago)
- Early PEX systems still have good lifespan
- Unused for ~10 years
- Modern PEX from that era robust and reliable
Critical: Professional Pressure Test
Must perform before connecting boiler:
- Pressure test entire system
- Check for leaks at all joints
- Inspect manifolds and connections
- Verify all zones functional
- Check circulation pump
- Inspect expansion vessel
Why This Matters:
- Identifies any damage before filling system
- Prevents water damage to house
- Ensures safe operation
- Required for insurance
- Needed for grant documentation
Likely Scenarios:
Best Case (Most Probable):
- System intact and serviceable
- Maybe some minor repairs needed
- Clean and pressurize
- Connect boiler and go
Medium Case:
- Some joints need resealing
- Manifolds need servicing
- Minor repairs manageable
- Still cost-effective vs. new system
Worst Case (Unlikely):
- Significant damage requiring extensive repair
- Even then, likely cheaper than new radiator system
Approach:
- Professional pressure test
- Address any issues found
- Install budget boiler (gas/oil)
- Connect to existing underfloor system
- Get house warm immediately
Why Budget Boiler First:
- Quick heating solution
- Lower upfront cost
- Time to assess insulation needs
- Wait for SEAI grant timing
- Flexibility to upgrade later
Budget: Within Vacant Property Grant
Timing: After proper insulation installed
Funding: SEAI Better Energy Homes grant
Advantages of Underfloor + Heat Pump:
- Ideal combination
- Underfloor works at lower temperatures
- Heat pumps most efficient at lower temps
- Perfect match for energy efficiency
Process:
- Install adequate insulation
- Apply for SEAI grant
- Select approved contractor
- Install heat pump
- Connect to existing underfloor
- Remove budget boiler
See: SEAI Better Energy Homes and Heat Pump Planning
¶ Main Elements
Distribution System:
- PEX pipes embedded in floor
- Divided into heating zones
- Each zone controllable separately
Manifolds:
- Central distribution points
- Flow and return for each zone
- Usually in accessible location
- May need servicing
Circulation Pump:
- Moves heated water through system
- May need replacement after 10 years unused
- Relatively inexpensive component
Controls:
- Thermostats for each zone
- May need upgrading
- Modern smart controls available
Expansion Vessel:
- Handles water expansion when heated
- Check pressure and condition
Find:
- Heating engineer familiar with underfloor systems
- Experience with PEX systems
- Can perform pressure testing
- Can provide written report
Assessment Should Include:
- Visual inspection of accessible components
- Pressure test (critical)
- Manifold inspection
- Pump condition
- Controls assessment
- Recommendations for reconnection
- Cost estimate for any repairs
- Written report for grant application
Need:
- Professional assessment report
- Pressure test results
- Photos of system components
- Scope of work for reconnection
- Cost estimates
- Confirmation system serviceable
If System Sound:
- Pressure testing: €200-400
- Minor repairs/servicing: €500-1,000
- Budget boiler: €2,000-3,000
- Installation/connection: €1,000-1,500
- Total: €3,700-5,900
vs. New Radiator System:
- Radiators and pipes throughout house: €8,000-12,000+
- Installation labor: €3,000-5,000+
- Total: €11,000-17,000+
Savings: €5,000-11,000+ by using existing system
Vacant Property Grant Covers:
- Pressure testing
- System repairs/servicing
- Budget boiler purchase
- Installation and connection
Unlikely but possible:
If extensive damage found and repair not economical:
Options:
- Install new underfloor (expensive)
- Install radiator system (cheaper than new underfloor)
- Combination (underfloor in some areas, radiators others)
Decision Factors:
- Cost comparison
- Timeline impact
- Long-term efficiency goals
- Grant coverage
Still Better Than Starting from Scratch:
At least we know layout and requirements
- PEX Durability: Modern PEX from 1990s-2000s very reliable
- Unused is Better: No wear from use, no corrosion
- Professional Installation: Original installation likely quality
- Common Success: Many revived systems work fine
- Cost-Effective Even with Repairs: Still cheaper than new
Even if repairs needed:
- Still valuable existing infrastructure
- Cheaper than installing from scratch
- Worth repairing for heat pump compatibility
- Long-term efficiency benefits
Last updated: December 18, 2024